A264150 Numerators of SGGS((2*n+1)/2^(n+1)) where the rational numbers SGGS(n) are defined in A264148.

1, -1, 1, 1, -281, -5221, 5459, 91207079, -2650986803, -6171801683, 4283933145517, 11963983648109, -208697624924077, -29320119130515566117, 2700231121460756431181, 10084288256532215186381, -6782242429223267933535073, -51748587106835353426330148693

Offset: 0

Author

Peter Luschny, Nov 05 2015

Keywords

• sign
• frac

Comments

See A264148 for definitions and cross-references.

Links

• G. C. Greubel, Table of n, a(n) for n = 0..255

Crossrefs

Cf. A264148, denominators in A065973.

Programs

Maple

h := proc(k) option remember; local j; `if`(k<=0, 1,
(h(k-1)/k-add((h(k-j)*h(j))/(j+1), j=1..k-1))/(1+1/(k+1))) end:
SGGS := n -> h(n)*doublefactorial(n-1):
A264150 := n -> numer(SGGS(2*n+1)/2^(n+1)): seq(A264150(n), n=0..17);

Mathematica

h[k_]:= h[k] = If[k <= 0, 1, (h[k - 1]/k - Sum[h[k - j]*h[j]/(j + 1), {j, 1, k - 1}])/(1 + 1/(k + 1))]; b[n_] := h[n]*Factorial2[n - 1]; Table[ Numerator[b[2*n + 1]/2^(n + 1)], {n,0,50}] (* G. C. Greubel, Feb 08 2018 *)