OFFSET
1,1
COMMENTS
Except for first three terms, a(n) is 10 times 2^(n-4).
These values comprise the tile values used in the "fives" variant of the game 2048, including 1 as the zeroth term. - Michael De Vlieger, Jul 18 2018
LINKS
Colin Barker, Table of n, a(n) for n = 1..1000
E. R. Berlekamp, A contribution to mathematical psychometrics, Unpublished Bell Labs Memorandum, Feb 08 1968 [Annotated scanned copy]
David Eppstein, Making Change in 2048, arXiv:1804.07396 [cs.DM], 2018.
Index entries for linear recurrences with constant coefficients, signature (2).
FORMULA
a(n) = A020714(n-3) for n>2.
a(n) = A146523(n-2) for n>2. - R. J. Mathar, May 14 2015
G.f.: x*(1 - x)*(2 + x) / (1 - 2*x). - Colin Barker, Nov 17 2018
MATHEMATICA
t = {2, 3}; For[k = 3, k <= 27, k++, AppendTo[t, Total@ t]]; t (* Michael De Vlieger, May 14 2015 *)
Join[{2, 3}, Table[5 2^n, {n, 0, 40}]] (* Vincenzo Librandi, May 15 2015 *)
Join[{2, 3}, NestList[2#&, 5, 40]] (* Harvey P. Dale, Apr 06 2018 *)
PROG
(Magma) [2, 3] cat [5*2^n: n in [0..35]]; // Vincenzo Librandi, May 15 2015
(PARI) a(n) = if(n<3, n+1, 5*2^(n-3)); \\ Altug Alkan, Jul 18 2018
(PARI) Vec(x*(1 - x)*(2 + x) / (1 - 2*x) + O(x^40)) \\ Colin Barker, Nov 17 2018
(PARI) a(n) = ceil(5*2^(n-3)) \\ Alan Michael Gómez Calderón, Mar 30 2022
CROSSREFS
KEYWORD
nonn,easy,less
AUTHOR
Giovanni Teofilatto, Apr 24 2015
STATUS
approved