OFFSET
0,2
LINKS
Alois P. Heinz, Table of n, a(n) for n = 0..435
FORMULA
E.g.f.: exp(x)*(1 + 3*x + x^2)/(1 + exp(x)*x*(1 + x)). - Ilya Gutkovskiy, Mar 06 2018
MAPLE
logtr:= proc(p) local b; b:= proc(n) option remember; if n=0 then 1 else p(n)- add(k *binomial(n, k) *p(n-k) *b(k), k=1..n-1)/n fi end; n->b(n+1) end: a:= logtr(n-> n^2): seq(a(n), n=0..25); # Alois P. Heinz, Sep 14 2008
MATHEMATICA
With[{nn=30}, CoefficientList[Series[(Exp[x](1+3x+x^2))/(1+Exp[x]x(1+x)), {x, 0, nn}], x] Range[0, nn]!] (* Harvey P. Dale, Feb 03 2019 *)
CROSSREFS
KEYWORD
sign
AUTHOR
STATUS
approved