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.

A066268 Product of first n primorials - 1.

Original entry on oeis.org

1, 11, 359, 75599, 174635999, 5244319079999, 2677277333530799999, 25968760179275365451999999, 5793445238736255798985527239999999, 37481813439427687898244906452608585199999999, 7517370874372838151564668004911177464757864075999999999
Offset: 1

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Author

Patrick De Geest, Dec 16 2001

Keywords

Examples

			a(3) = (2)*(2*3)*(2*3*5) - 1 = 359.
		

Crossrefs

Programs

  • Mathematica
    Table[Times@@Table[Times@@Prime[Range[n]],{n,k}]-1,{k,40}]
    (* or *)
    pr2=1; Table[pr1=1; Do[pr1=pr1*Prime[n],{n,k}]; pr2=pr2*pr1; pr2-1,{k,40}] (* Jayanta Basu, May 12 2013 *)
  • PARI
    a(n) = -1 + prod(k=1, n, prime(k)^(n-k+1)) \\ Andrew Howroyd, Dec 10 2024

Formula

a(n) = A006939(n) - 1. - Andrew Howroyd, Dec 10 2024

Extensions

Offset changed from 0 to 1 by Harry J. Smith, Feb 08 2010