OFFSET
0,4
COMMENTS
The denominators are various powers of 2.
LINKS
D. Barsky, J.-P. Bézivin, p-adic Properties of Lengyel's Numbers, Journal of Integer Sequences, 17 (2014), #14.7.3.
EXAMPLE
The sequence Z^(2)(n) begins 0, 1, 1/2, 5/4, 6, 399/8, 10137/16, 364737/32, 2206077/8, 276269667/32, 21732613641/64, 2097942773859/128, 60958311638283/64, 16792338947372883/256, 2704712327221326273/512,...
MAPLE
Z:=proc(n, p) option remember; local k; if n <= 1 then n else add(stirling2(n, k)*Z(k, p)/(p-1), k=1..n-1); fi; end;
t1:=[seq(Z(n, 2), n=0..35)];
CROSSREFS
KEYWORD
nonn
AUTHOR
N. J. A. Sloane, Aug 22 2014
STATUS
approved