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 A137988 Decimal expansion of the number whose Pierce expansion has the sequence of double factorial numbers (A000165) as coefficients. 5
 3, 5, 2, 8, 0, 6, 4, 3, 8, 1, 0, 6, 6, 5, 0, 0, 3, 6, 4, 6, 2, 1, 2, 3, 6, 0, 5, 3, 1, 0, 7, 3, 0, 0, 8, 6, 3, 1, 1, 1, 4, 5, 9, 6, 9, 4, 4, 4, 9, 9, 0, 1, 7, 4, 0, 2, 7, 4, 9, 4, 6, 3, 1, 0, 7, 1, 8, 6, 4, 7, 0, 1, 5, 3, 3, 6, 5, 6, 5, 4, 4, 1, 4, 5, 6, 9, 0, 9, 1, 8, 9, 6, 0, 9, 4, 8, 3, 3, 9 (list; constant; graph; refs; listen; history; text; internal format)
 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 Cf. A000142, A137986, A137987, A137989. Sequence in context: A208754 A180077 A095749 * A258367 A160092 A282348 Adjacent sequences: A137985 A137986 A137987 * A137989 A137990 A137991 KEYWORD easy,nonn,cons AUTHOR Paolo P. Lava and Giorgio Balzarotti, Feb 26 2008 STATUS approved

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Last modified November 29 03:03 EST 2023. Contains 367422 sequences. (Running on oeis4.)