OFFSET
1,4
COMMENTS
See A192232.
FORMULA
Conjecture: a(n) +2*(-n+1)*a(n-1) +(n^2-3*n+1)*a(n-2)=0. - R. J. Mathar, May 04 2014
MATHEMATICA
q[x_] := x + 1;
p[0, x_] := 1; p[1, x_] := x;
p[n_, x_] := (x + n) p[n - 1, x] /; n > 1
reductionRules = {x^y_?EvenQ -> q[x]^(y/2),
x^y_?OddQ -> x q[x]^((y - 1)/2)};
t = Table[
Last[Most[
FixedPointList[Expand[#1 /. reductionRules] &, p[n, x]]]], {n, 0,
20}]
Table[Coefficient[Part[t, n], x, 0], {n, 1, 20}] (* A192238 *)
Table[Coefficient[Part[t, n], x, 1], {n, 1, 20}] (* A192239 *)
(* by Peter J. C. Moses, Jun 25 2011 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Clark Kimberling, Jun 26 2011
STATUS
approved