OFFSET
0,2
LINKS
Bruno Berselli, Table of n, a(n) for n = 0..1000
Index entries for linear recurrences with constant coefficients, signature (3,-3,1).
FORMULA
G.f.: (1+x)*(1+21*x+x^2)/(1-x)^3. - Bruno Berselli, Feb 06 2012
E.g.f.: (x*(x+1)*23+2)*e^x-1. - Gopinath A. R., Feb 14 2012
Sum_{n>=0} 1/a(n) = 3/4 + sqrt(46)/92*Pi*coth( Pi*sqrt(46)/23) = 1.0677349581... - R. J. Mathar, May 07 2024
MATHEMATICA
Join[{1}, 23 Range[41]^2 + 2] (* Bruno Berselli, Feb 06 2012 *)
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
STATUS
approved