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Search: a121854 -id:a121854
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a(n) = ceiling(n*Pi).
+10
5
0, 4, 7, 10, 13, 16, 19, 22, 26, 29, 32, 35, 38, 41, 44, 48, 51, 54, 57, 60, 63, 66, 70, 73, 76, 79, 82, 85, 88, 92, 95, 98, 101, 104, 107, 110, 114, 117, 120, 123, 126, 129, 132, 136, 139, 142, 145, 148, 151, 154, 158, 161, 164, 167, 170, 173, 176, 180, 183, 186
OFFSET
0,2
LINKS
MATHEMATICA
Table[Ceiling[n Pi], {n, 0, 80}] (* Vincenzo Librandi, Feb 22 2013 *)
PROG
(PARI) for(n=0, 50, print1(ceil(n*Pi), ", ")) \\ G. C. Greubel, Oct 28 2017
(Magma) [Ceiling(n*Pi): n in [0..50]]; // G. C. Greubel, Oct 28 2017
CROSSREFS
Essentially the same as A004084. Cf. A022844, A121854, A121855.
KEYWORD
nonn,easy
AUTHOR
Mohammad K. Azarian, Sep 06 2006
STATUS
approved
a(n) = ceiling(e^(n*Pi)).
+10
4
1, 24, 536, 12392, 286752, 6635624, 153552936, 3553321281, 82226315586, 1902773895293, 44031505860633, 1018919543279305, 23578503968558227, 545622913077172101, 12626092124920479898, 292176517015939695008
OFFSET
0,2
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 0..699 [Offset shifted by Georg Fischer, Sep 02 2022]
MATHEMATICA
Ceiling[E^(Pi Range[0, 20])] (* Vincenzo Librandi, Feb 21 2013 *)
PROG
(PARI) for(n=0, 50, print1(ceil(exp(Pi*n)), ", ")) \\ G. C. Greubel, Nov 06 2017
(Magma) C<i> := ComplexField(); [Ceiling(Exp(Pi(C)*n)): n in [0..50]]; // G. C. Greubel, Nov 06 2017
CROSSREFS
Cf. A062360 (floor).
KEYWORD
nonn,easy
AUTHOR
Mohammad K. Azarian, Sep 01 2006
EXTENSIONS
Offset changed to 0 by Georg Fischer, Sep 02 2022
STATUS
approved
a(n) = floor((Pi+e)^(n*Pi)).
+10
4
1, 258, 66801, 17265408, 4462406595, 1153350806021, 298094324981778, 77045272021641916, 19913072619720776032, 5146720243221262934093, 1330218081751512472685763, 343807329988307215923432746, 88860226586342124489251555256, 22966758356328845813340839281381
OFFSET
0,2
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 0..399 [Offset shifted by Georg Fischer, Sep 02 2022]
MATHEMATICA
With[{c=\[Pi]+E}, Floor[c^(\[Pi] Range[0, 20])]] (* Harvey P. Dale, Mar 20 2011 *)
PROG
(PARI) for(n=0, 50, print1(floor((Pi+exp(1))^(n*Pi)), ", ")) \\ G. C. Greubel, Nov 06 2017
(Magma) C<i> := ComplexField(); [Floor((Pi(C)+Exp(1))^(n*Pi(C))): n in [0..50]]; // G. C. Greubel, Nov 06 2017
KEYWORD
nonn,easy
AUTHOR
Mohammad K. Azarian, Sep 02 2006
EXTENSIONS
Offset changed to 0 by Georg Fischer, Sep 02 2022
STATUS
approved
The total number of elastic collisions between a block of mass n, a block of mass 1, and a wall.
+10
4
3, 5, 5, 6, 7, 8, 8, 9, 9, 10, 10, 11, 11, 12, 12, 12, 13, 13, 13, 14, 14, 14, 15, 15, 15, 16, 16, 16, 17, 17, 17, 17, 18, 18, 18, 19, 19, 19, 19, 20, 20, 20, 20, 20, 21, 21, 21, 21, 22, 22, 22, 22, 23, 23, 23, 23, 23, 24, 24, 24, 24, 24, 25, 25, 25, 25, 25
OFFSET
1,1
COMMENTS
Suppose there is a block A of mass n sliding left toward a stationary block B of mass 1, to the left of which is a wall. Assuming the sliding is frictionless and the collisions are elastic, a(n) is the number of collisions between A and B plus the number of collisions between B and the wall. (See Grant Sanderson links for animated examples.)
a(100^n) = A011545(n).
Since arctan(sqrt(1/n)) is approximately sqrt(1/n) for large values of n, a(n) = A121854(n) for most values of n.
Conjecture: The values of n for which a(n) != A121854(n) is a subset of A331903.
Initial phase:
\ | ______________________
\ \| | |
\ | | |
\ \| | |
\ | | |
\ \| <=== | Block A |
\ | _________ | |
\ \| | | | M = n |
\ | | Block B | | |
\ \| | | | | |
\ | | M = 1 | | |
\ \| |_________| |______________________|
\ L----------------------------------------------------------
\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \
\ \|
\ | ______________________
\ \| | |
\ | | |
\ \| | |
\ | | |
\ \| <=== | |
\ | _________ | |
\ \| | || |
\ | | || |
\ \| | || |
\ | | || |
\ \| |_________||______________________|
\ L----------------------------------------------------------
\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \
\ \|
\ | ______________________
\ \| | |
\ | | |
\ \| | |
\ | | |
\ \| <== | |
\ | _________ | |
\ \| | | | |
\ | | | | |
\ \|<===>| | | |
\ | | | | |
\ \| |_________| |______________________|
\ L----------------------------------------------------------
\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \
LINKS
Code Golf Stack Exchange, Elastic collisions between blocks
Grant Sanderson, How Pi Connects Colliding Blocks to a Quantum Search Algorithm, Quanta Magazine (2020).
Grant Sanderson, The most unexpected answer to a counting puzzle, 3Blue1Brown video (2019)
Grant Sanderson, Why do colliding blocks compute pi?, 3Blue1Brown video (2019)
FORMULA
a(n) = ceiling(Pi/arctan(sqrt(1/n))) - 1.
MATHEMATICA
Table[Ceiling[Pi/ArcTan[Sqrt[1/n]] - 1], {n, 1, 100}]
CROSSREFS
KEYWORD
nonn
AUTHOR
Peter Kagey, Jan 29 2020
STATUS
approved
a(n) = ceiling((Pi - e)*sqrt(n)).
+10
3
0, 1, 1, 1, 1, 1, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5
OFFSET
0,7
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 0..999 [Offset shifted by Georg Fischer, Sep 02 2022]
MATHEMATICA
Table[Ceiling[(Pi - E) Sqrt[n]], {n, 0, 110}] (* Vincenzo Librandi, Feb 21 2013 *)
PROG
(PARI) for(n=0, 50, print1(ceil((Pi - exp(1))*sqrt(n)), ", ")) \\ G. C. Greubel, Oct 28 2017
(Magma) C<i> := ComplexField(); [Ceiling((Pi(C) - Exp(1))*Sqrt(n)): n in [0..50]]; // G. C. Greubel, Oct 28 2017
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Mohammad K. Azarian, Sep 01 2006
EXTENSIONS
Offset corrected by Mohammad K. Azarian, Nov 20 2008
Offset changed to 0 by Georg Fischer, Sep 02 2022
STATUS
approved
a(n) = floor(Pi^(n*e)).
+10
3
1, 22, 504, 11328, 254433, 5714356, 128339632, 2882400037, 64736277048, 1453922256329, 32653869265129, 733378399940296, 16471061151498380, 369926160190271626, 8308229975861003525, 186595847388277259847, 4190785566084546949287, 94121513992523815815369
OFFSET
0,2
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 0..699 [Offset shifted by Georg Fischer, Sep 02 2022]
MATHEMATICA
Floor[Pi^(E Range[0, 20])] (* Vincenzo Librandi, Feb 21 2013 *)
PROG
(PARI) for(n=0, 50, print1(floor(Pi^(n*exp(1))), ", ")) \\ G. C. Greubel, Nov 06 2017
(Magma) C<i> := ComplexField(); [Floor(Pi(C)^(n*Exp(1))): n in [0..50]]; // G. C. Greubel, Nov 06 2017
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Mohammad K. Azarian, Sep 01 2006
EXTENSIONS
Offset changed to 0 by Georg Fischer, Sep 02 2022
STATUS
approved
a(n) = ceiling((Pi+e)^(n*e)).
+10
3
1, 123, 14952, 1828145, 223535960, 27332807666, 3342112728282, 408656059975458, 49968325108097956, 6109865382293662598, 747082374864324679925, 91349324397617876090444, 11169717488538903806777418, 1365774619533204572560235118
OFFSET
0,2
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 0..399 [Offset shifted by Georg Fischer, Sep 02 2022]
MATHEMATICA
Ceiling[(Pi + E)^(E (Range[0, 20]))] (* Vincenzo Librandi, Feb 21 2013 *)
PROG
(PARI) for(n=0, 50, print1(ceil((Pi+exp(1))^(n*exp(1))), ", ")) \\ G. C. Greubel, Nov 06 2017
(Magma) C<i> := ComplexField(); [Ceiling((Pi(C)+Exp(1))^(n*Exp(1))): n in [0..50]]; // G. C. Greubel, Nov 06 2017
KEYWORD
nonn,easy
AUTHOR
Mohammad K. Azarian, Sep 02 2006
EXTENSIONS
Offset changed to 0 by Georg Fischer, Sep 02 2022
STATUS
approved
a(n) = ceiling(n*(e^Pi + Pi^e)).
+10
3
0, 46, 92, 137, 183, 228, 274, 320, 365, 411, 456, 502, 548, 593, 639, 684, 730, 776, 821, 867, 912, 958, 1004, 1049, 1095, 1140, 1186, 1232, 1277, 1323, 1368, 1414, 1460, 1505, 1551, 1596, 1642, 1688, 1733, 1779, 1824, 1870, 1916, 1961, 2007, 2052, 2098
OFFSET
0,2
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 0..999 [Offset shifted by Georg Fischer, Sep 02 2022]
MAPLE
A121929:=n->ceil((n-1)*(exp(1)^Pi+Pi^exp(1))): seq(A121929(n), n=1..100); # Wesley Ivan Hurt, Jan 21 2017
MATHEMATICA
With[{a = E^Pi + Pi^E}, Ceiling[a Range[0, 80]]] (* Vincenzo Librandi, Feb 21 2013 *)
PROG
(PARI) for(n=0, 50, print1(ceil(n*(Pi^exp(1)+exp(Pi))), ", ")) \\ G. C. Greubel, Nov 06 2017
(Magma) C<i> := ComplexField(); [Ceiling(n*(Pi(C)^Exp(1) + Exp(1)^Pi(C))): n in [0..50]]; // G. C. Greubel, Nov 06 2017
KEYWORD
nonn,easy
AUTHOR
Mohammad K. Azarian, Sep 02 2006
EXTENSIONS
Offset corrected by Mohammad K. Azarian, Nov 20 2008
Offset changed to 0 by Georg Fischer, Sep 02 2022
STATUS
approved
a(n) = floor(n*(e^Pi - Pi^e)).
+10
3
0, 0, 1, 2, 2, 3, 4, 4, 5, 6, 6, 7, 8, 8, 9, 10, 10, 11, 12, 12, 13, 14, 14, 15, 16, 17, 17, 18, 19, 19, 20, 21, 21, 22, 23, 23, 24, 25, 25, 26, 27, 27, 28, 29, 29, 30, 31, 32, 32, 33, 34, 34, 35, 36, 36, 37, 38, 38, 39, 40, 40, 41, 42, 42, 43, 44, 44, 45, 46, 47, 47, 48, 49, 49
OFFSET
0,4
COMMENTS
Beatty sequence of A063504. - R. J. Mathar, Aug 11 2012
LINKS
MATHEMATICA
With[{c=E^Pi-Pi^E}, Floor[c*Range[0, 80]]] (* Harvey P. Dale, Jan 06 2012 *)
PROG
(PARI) for(n=0, 50, print1(floor(n*(exp(Pi) - Pi^exp(1))), ", ")) \\ G. C. Greubel, Nov 06 2017
(Magma) C<i> := ComplexField(); [Floor(n*(Exp(1)^Pi(C) - Pi(C)^Exp(1) )): n in [0..50]]; // G. C. Greubel, Nov 06 2017
CROSSREFS
KEYWORD
nonn
AUTHOR
Mohammad K. Azarian, Sep 02 2006
STATUS
approved
a(n) = ceiling((Pi + e)*sqrt(n)).
+10
2
0, 6, 9, 11, 12, 14, 15, 16, 17, 18, 19, 20, 21, 22, 22, 23, 24, 25, 25, 26, 27, 27, 28, 29, 29, 30, 30, 31, 32, 32, 33, 33, 34, 34, 35, 35, 36, 36, 37, 37, 38, 38, 38, 39, 39, 40, 40, 41, 41, 42, 42, 42, 43, 43, 44, 44, 44, 45, 45, 46, 46, 46, 47, 47, 47, 48, 48, 48, 49, 49
OFFSET
0,2
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 0..999 [Offset shifted by Georg Fischer, Sep 02 2022]
MATHEMATICA
Table[Ceiling[(Pi + E) Sqrt[n]], {n, 0, 70}] (* Vincenzo Librandi, Feb 21 2013 *)
PROG
(PARI) for(n=0, 50, print1(ceil((exp(1)+Pi)*sqrt(n)), ", ")) \\ G. C. Greubel, Oct 28 2017
(Magma) C<i> := ComplexField(); [Ceiling((Exp(1) + Pi(C))*Sqrt(n)): n in [0..50]]; // G. C. Greubel, Oct 28 2017
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Mohammad K. Azarian, Sep 01 2006
EXTENSIONS
Offset corrected by Mohammad K. Azarian, Nov 20 2008
Offset changed to 0 by Georg Fischer, Sep 02 2022
STATUS
approved

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