

A137987


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


7



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
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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 A020809
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



