OFFSET
0,2
LINKS
Amiram Eldar, Table of n, a(n) for n = 0..10000
Eric Weisstein's MathWorld, Polygamma Function.
Wikipedia, Polygamma Function.
Index entries for linear recurrences with constant coefficients, signature (4,-6,4,-1).
FORMULA
Sum_{n>=0} 1/a(n) = -polygamma(2, 1/5)/250. - Amiram Eldar, Oct 02 2020
From Wesley Ivan Hurt, Oct 02 2020: (Start)
a(n) = 4*a(n-1) - 6*a(n-2) + 4*a(n-3) - a(n-4).
G.f.: (1+212*x+473*x^2+64*x^3)/(-1+x)^4. (End)
From Stefano Spezia, Nov 01 2024: (Start)
E.g.f.: exp(x)*(1 + 215*x + 450*x^2 + 125*x^3). (End)
EXAMPLE
a(0) = (5*0 + 1)^3 = 1.
MATHEMATICA
Table[(5*n + 1)^3, {n, 0, 25}] (* Amiram Eldar, Oct 02 2020 *)
CROSSREFS
KEYWORD
nonn,easy,changed
AUTHOR
STATUS
approved