OFFSET
0,1
LINKS
G. C. Greubel, Table of n, a(n) for n = 0..5000
Eric W. Weisstein, Pierce Expansion.
Eric W. Weisstein, Engel Expansion.
MAPLE
P:=proc(n) local a, i, j, k, w; a:=0; w:=1; for i from 0 by 1 to n do k:=i; j:=i-2; while j>0 do k:=k*j; j:=j-2; od; if (i=0 or i=1) then k:=1; fi; if i=2 then k:=2; fi; w:=w*k; a:=a+(-1)^i/w; print(evalf(a, 100)); od; end: P(100);
MATHEMATICA
RealDigits[N[(Sum[(-1)^n*Product[1/((k + 1)!!), {k, 1, n}], {n, 1, 250}]), 100]][[1]] (* G. C. Greubel, Jan 01 2017 *)
CROSSREFS
KEYWORD
AUTHOR
Paolo P. Lava and Giorgio Balzarotti, Feb 26 2008
STATUS
approved