[go: up one dir, main page]

login
Search: a162522 -id:a162522
     Sort: relevance | references | number | modified | created      Format: long | short | data
Magic numbers A018226 divided by 2.
+10
7
1, 4, 10, 14, 25, 41, 63
OFFSET
1,2
COMMENTS
Sequence related to atomic nuclei.
KEYWORD
fini,full,nonn
AUTHOR
Omar E. Pol, Jul 06 2009
STATUS
approved
First differences of magic numbers A018226, divided by 2.
+10
7
3, 6, 4, 11, 16, 22
OFFSET
1,1
COMMENTS
Sequence related to atomic nucleus.
FORMULA
a(n) = A162522(n)/2.
KEYWORD
fini,full,nonn
AUTHOR
Omar E. Pol, Jul 06 2009
STATUS
approved
Partial sums of magic numbers A018226.
+10
7
2, 10, 30, 58, 108, 190, 316
OFFSET
1,1
COMMENTS
Sequence related to atomic nuclei.
KEYWORD
fini,full,nonn
AUTHOR
Omar E. Pol, Jul 06 2009
EXTENSIONS
Edited by Omar E. Pol, Jul 16 2009
STATUS
approved
Partial sums of magic numbers A018226, divided by 2.
+10
7
1, 5, 15, 29, 54, 95, 158
OFFSET
1,2
COMMENTS
Sequence related to atomic nuclei.
FORMULA
a(n) = A162524(n)/2.
KEYWORD
fini,full,nonn
AUTHOR
Omar E. Pol, Jul 06 2009
STATUS
approved
Characteristic function of magic numbers A018226: 1 if n is a magic number else 0.
+10
3
0, 1, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1
OFFSET
1,1
COMMENTS
Sequence related to atomic nuclei.
PROG
(PARI) A162518(n) = if(n<1, 0, polcoeff( x^126+x^82+x^50+x^28+x^20+x^8+x^2, n)); \\ Antti Karttunen, Dec 24 2018, after code in A089011
KEYWORD
nonn
AUTHOR
Omar E. Pol, Jul 07 2009
EXTENSIONS
Data section extended up to a(126) by Antti Karttunen, Dec 24 2018
STATUS
approved
If 0 <= n <= 3 then a(n) = n(n+1)(n+2)/3, if n >= 4 then a(n) = n(n^2+5)/3.
+10
3
0, 2, 8, 20, 28, 50, 82, 126, 184, 258, 350, 462, 596, 754, 938, 1150, 1392, 1666, 1974, 2318, 2700, 3122, 3586, 4094, 4648, 5250, 5902, 6606, 7364, 8178, 9050, 9982, 10976, 12034, 13158, 14350, 15612, 16946, 18354, 19838, 21400, 23042, 24766, 26574
OFFSET
0,2
COMMENTS
One way to generalize the magic number sequence in A018226.
See also A130598 and A162630.
FORMULA
From Daniel Forgues, May 03 2011: (Start)
If 0 <= n <= 3 then a(n) = 2 T_n, otherwise a(n) = 2 (T_n - t_{n-1}), where T_n is the n-th tetrahedral number, t_n the n-th triangular number.
G.f.: (2*x*(1 - 6*x^3 + 14*x^4 - 11*x^5 + 3*x^6))/(1 - x)^4, n >= 0.
(End)
a(n) = n*(n^2+5)/3 + (4*n-6)*A171386(n). - Omar E. Pol, Aug 14 2013
KEYWORD
easy,nonn
AUTHOR
Omar E. Pol, Jul 07 2009, Jul 13 2009
EXTENSIONS
Edited by N. J. A. Sloane, Jul 18 2009
STATUS
approved
Characteristic function of magic numbers A018226: 0 if n is a magic number else 1.
+10
2
1, 0, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1
OFFSET
1,1
COMMENTS
Also, successive digits of A130598.
This sequence is related to atomic nuclei. See also A162518.
KEYWORD
fini,nonn
AUTHOR
Omar E. Pol, Jul 07 2009
STATUS
approved
Number of states in the n-th shell of the nuclear shell model.
+10
2
2, 6, 12, 8, 22, 32, 44, 58
OFFSET
1,1
COMMENTS
Partial sums of the first seven terms give the "magic numbers" A018226.
Also the partial sums of the first eight terms give the positive first eight terms of A162626 (and possibly more).
REFERENCES
M. Goeppert Mayer and J. Hans D. Jensen, Elementary Theory of Nuclear Shell Structure, J. Wiley and Sons, Inc. (1955).
I. Talmi, Simple Models of Complex Nuclei, Hardwood Academic Publishers (1993).
CROSSREFS
KEYWORD
nonn,hard,more
AUTHOR
Omar E. Pol, Jun 04 2012
STATUS
approved

Search completed in 0.007 seconds