cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A048834 Decimal expansion of Sum_{n >= 2} (K(n)/n!), where K(n) is A002034.

Original entry on oeis.org

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

Views

Author

Charles T. Le (charlestle(AT)yahoo.com)

Keywords

Comments

This constant was proved to be irrational by Cojocaru and Cojocaru (1996). - Amiram Eldar, Jul 07 2021

Examples

			1.71400629359161602272774384541903375483159792171895...
		

Crossrefs

Programs

  • Maple
    Digits := 80 ; A002034:=[1,2,3,4,5,3,7,4,6,5,11,4,13,7,5,6,17,6,19,5,7,11,23,4,10,13,9,7,29,5,31,8,11,17,7,6,37,19,13,5,41,7,43,11,6,23,47,6,14,10,17,13,53,9,11,7,19,29,59,5,61,31,7,8,13,11,67,17,23,7,71,6,73,37,10,19,11,13,79,6,9,41,83,7]; sma := 0.0 ; for n from 2 to nops(A002034) do sma := sma + A002034[n]/factorial(n) ; od ; # R. J. Mathar, Apr 13 2006
  • Mathematica
    K[n_] := Module[{k = 1}, While[True, If[Divisible[k!, n], Return[k], k++]]];
    N[Sum[K[n]/n! , {n, 2, 200}], 103] // RealDigits // First (* Jean-François Alcover, Nov 17 2020 *)

Extensions

More terms from R. J. Mathar, Apr 13 2006
More terms from Jean-François Alcover, Nov 17 2020