OFFSET
0,2
LINKS
Colin Barker, Table of n, a(n) for n = 0..1000
Index entries for linear recurrences with constant coefficients, signature (8,-14,8,-1).
FORMULA
a(n) = Sum_{k=0...n} A001652(k).
a(n) = A000129(n+1)^2-floor((n+2)/2); e.g. 0=1^2-1 and 166460=408^2-4.
G.f.: -x*(-3+x) / ( (1-6*x+x^2)*(x-1)^2 ). - R. J. Mathar, Feb 05 2016
a(n) = (-6 + (3-2*sqrt(2))^(1+n) + 3*(3+2*sqrt(2))^n + 2*sqrt(2)*(3+2*sqrt(2))^n - 4*n) / 8. - Colin Barker, Aug 10 2018
PROG
(PARI) concat(0, Vec(-x*(-3+x)/((1-6*x+x^2)*(x-1)^2) + O(x^40))) \\ Michel Marcus, Feb 05 2016
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Charlie Marion, Jan 11 2004
STATUS
approved