OFFSET
0,3
LINKS
Harvey P. Dale, Table of n, a(n) for n = 0..1000
Minerva Catral, P. L. Ford, P. E. Harris, S. J. Miller, et al. Legal Decompositions Arising from Non-positive Linear Recurrences, arXiv preprint arXiv:1606.09312 [math.CO], 2016. See Table 2.
Index entries for linear recurrences with constant coefficients, signature (2,-1,0,0,1,-1).
FORMULA
Partial sums of A003520 (with leading zero).
G.f.: x / ( (x-1)*(x^2-x+1)*(x^3+x^2-1) ).
a(n) = 2a(n-1)-a(n-2)+a(n-5)-a(n-6).
7*a(n) = A117373(n+2) -7 +10*b(n) +15*b(n-1) +9*b(n-2), where b(n) = A182097(n). - R. J. Mathar, Aug 07 2017
a(n) = A003520(n+4) -1. - R. J. Mathar, Aug 07 2017
MATHEMATICA
LinearRecurrence[{2, -1, 0, 0, 1, -1}, {0, 1, 2, 3, 4, 5}, 50] (* Harvey P. Dale, Feb 20 2017 *)
PROG
(PARI) a(n) = sum(k=0, n\5, binomial(n-4*k, k+1)); \\ Michel Marcus, Jul 11 2018
CROSSREFS
KEYWORD
easy,nonn
AUTHOR
Paul Barry, Oct 22 2004
EXTENSIONS
Values from a(5) on corrected by R. J. Mathar, Jul 29 2008
STATUS
approved