A186944 Geometric mean of n-th row of A080508.

1, 2, 2, 6, 6, 30, 30, 210, 210, 210, 210, 2310, 2310, 30030, 30030, 30030, 30030, 510510, 510510, 9699690, 9699690, 9699690, 9699690, 223092870, 223092870, 223092870, 223092870, 223092870, 223092870, 6469693230, 6469693230, 200560490130, 200560490130

Offset: 1

Author

Michel Marcus, Aug 30 2013

Keywords

• nonn

Crossrefs

Cf. A080509, A083907, A034386.

Programs

PARI

a(n) = {if (n == 1, return (1)); if (n == 2, return (2)); f  = factor((n-1)!); prod(i=1, #f~, f[i,1]);} \\ Michel Marcus, Aug 30 2013

PARI

a(n) = if(n==2, 2, prod(i=1,primepi(n-1),prime(i))) \\ Jeppe Stig Nielsen, Nov 04 2018

Formula

For n != 2, a(n) = A034386(n-1). - Jeppe Stig Nielsen, Nov 04 2018