A137987 Decimal expansion of the inverse of the number whose Engel expansion has the sequence of factorial numbers (A000142) as coefficients.

3, 8, 6, 5, 7, 2, 8, 5, 1, 1, 2, 0, 0, 8, 5, 1, 2, 8, 5, 3, 8, 8, 3, 3, 5, 3, 0, 4, 8, 7, 3, 9, 2, 3, 2, 6, 8, 0, 1, 1, 2, 7, 2, 9, 8, 5, 8, 9, 2, 7, 4, 6, 4, 6, 8, 8, 9, 2, 5, 2, 2, 1, 3, 4, 4, 0, 4, 1, 0, 1, 1, 7, 3, 4, 1, 4, 5, 8, 4, 0, 7, 3, 3, 2, 1, 0, 1, 3, 6, 7, 0, 3, 3, 5, 9, 3, 9, 4, 7

Offset

0,1

Links

G. C. Greubel, Table of n, a(n) for n = 0..5000

Eric Weisstein's World of Mathematics, Pierce Expansion.

Eric Weisstein's World of Mathematics, Engel Expansion.

Formula

Equals 1/A287013. - Amiram Eldar, Nov 19 2020

Maple

P:=proc(n) local a, i, k; a:=0; k:=1; for i from 0 by 1 to n do k:=k*i!; a:=a+1/k; print(evalf(1/a, 100)); od; end: P(100);

Mathematica

RealDigits[N[(1/Sum[Product[1/((k - 1)!), {k, 1, n}], {n, 1, 250}]), 100]][[1]] (* G. C. Greubel, Jan 02 2017 *)

Crossrefs

Cf. A000142, A137986, A137988, A137989, A287013.

Sequence in context: A336079 A214726 A106291 * A212007 A187061 A363361

Adjacent sequences: A137984 A137985 A137986 * A137988 A137989 A137990

Keyword

easy,nonn,cons

Author

Paolo P. Lava and Giorgio Balzarotti, Feb 26 2008, Apr 18 2008

Status

approved