OFFSET
0,2
COMMENTS
Apart from initial term(s), dimension of the space of weight 2n cusp forms for Gamma_0( 36 ).
The positive terms are the differences of consecutive star numbers (A003154). - Mihir Mathur, Jun 07 2013
A089911(a(n)) = 0. - Reinhard Zumkeller, Jul 05 2013
a(1) = 12 is a primitive abundant number, thus all a(n), n >= 2, are nonprimitive abundant numbers. - Daniel Forgues, Sep 24 2016
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 0..2000
Tanya Khovanova, Recursive Sequences
INRIA Algorithms Project, Encyclopedia of Combinatorial Structures 324
Luis Manuel Rivera, Integer sequences and k-commuting permutations, arXiv preprint arXiv:1406.3081 [math.CO], 2014.
William A. Stein, Dimensions of the spaces S_k(Gamma_0(N))
William A. Stein, The modular forms database
Wikipedia, Star Number
Index entries for linear recurrences with constant coefficients, signature (2,-1).
FORMULA
a(n) = 12*n. a(n) = 2*a(n-1)-a(n-2) for n>1. G.f.: 12*x/(1-x)^2. - Vincenzo Librandi, Jun 11 2011
MAPLE
MATHEMATICA
12*Range[0, 200] (* Vladimir Joseph Stephan Orlovsky, Feb 19 2011 *)
NestList[12+#&, 0, 60] (* Harvey P. Dale, Feb 02 2022 *)
PROG
(Magma) [12*n: n in [0..50]]; // Vincenzo Librandi, Jun 11 2011
(Haskell)
a008594 = (* 12)
a008594_list = [0, 12 ..] -- Reinhard Zumkeller, Dec 12 2012
(PARI) a(n)=12*n \\ Charles R Greathouse IV, Apr 21 2015
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
STATUS
approved