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.

Showing 1-1 of 1 results.

A075055 Smallest integer of the form product (n+1)(n+2)...(n+k)/n!.

Original entry on oeis.org

1, 1, 6, 20, 70, 252, 7, 3432, 12870, 48620, 184756, 705432, 2704156, 10400600, 40116600, 178296, 601080390, 2333606220, 9075135300, 35345263800, 137846528820, 538257874440, 2104098963720, 8233430727600, 32247603683100, 126410606437752, 495918532948104
Offset: 0

Views

Author

Amarnath Murthy, Sep 07 2002

Keywords

Comments

Differs from A000984 at positions in A058008.

Examples

			a(6) = 7 = 7*8*9*10/6! = 5040/720.
		

Crossrefs

Cf. A075054.

Programs

  • Maple
    a:= proc(n) option remember; local k, t; t:= 1/n!;
          for k while denom(t)>1 do t:= t*(n+k) od; t
        end:
    seq(a(n), n=0..28);  # Alois P. Heinz, Feb 05 2025
  • Mathematica
    a[n_] := Catch[ For[ k = n-2, True, k++, If[ IntegerQ[an = (n+k)!/n!^2], Throw[an]]]]; a[1]=1; Table[a[n], {n, 1, 24}] (* Jean-François Alcover, Jun 28 2012 *)

Extensions

More terms from Sascha Kurz, Feb 02 2003
a(0)=1 prepended by Alois P. Heinz, Feb 05 2025
Showing 1-1 of 1 results.