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.

A066266 Product of first n primorials + 1.

Original entry on oeis.org

3, 13, 361, 75601, 174636001, 5244319080001, 2677277333530800001, 25968760179275365452000001, 5793445238736255798985527240000001, 37481813439427687898244906452608585200000001, 7517370874372838151564668004911177464757864076000000001
Offset: 1

Views

Author

Patrick De Geest, Dec 16 2001

Keywords

Examples

			a(3)=361 since 361 = (2)*(2*3)*(2*3*5) + 1.
		

Crossrefs

Programs

  • Mathematica
    Table[Times@@Table[Times@@Prime[Range[n]],{n,k}]+1,{k,40}] (* Jayanta Basu, May 12 2013 *)
    Rest[FoldList[Times,1,Rest[FoldList[Times,1,Prime[Range[10]]]]]]+1 (* Harvey P. Dale, Sep 16 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