A066120 Superduperprimorials: product of first n terms in Chernoff sequence.

1, 2, 24, 8640, 653184000, 114069441024000000, 598216546007097937920000000000, 1601591599167888308924824752807936000000000000000

Offset

0,2

Comments

First number with n distinct positive triangular exponents in its prime factorization. Subsequence of A025487. - Matthew Vandermast, Nov 05 2009; edited May 23 2012

Links

Harry J. Smith, Table of n, a(n) for n = 0..17

Formula

a(n) = Product_{i=1..n} prime(i)^((n-i+1)*(n-i+2)/2) = a(n-1)*A006939(n) = A066119(n-3, 4).

Example

a(4) = 2*(2*(2*3))*(2*(2*3)*(2*3*5)) = 2*(2*6)*(2*6*30) = 2*12*360 = 8640.

Prog

(PARI) a(n) = { my(p=primes(n)); prod(i=1, #p, p[i]^((n - i + 1)*(n - i + 2)/2)) } \\ Harry J. Smith, Feb 01 2010

Crossrefs

Cf. A000040, A002110, A006939, A055462, A166475.

Sequence in context: A203465 A055462 A088600 * A152687 A062716 A344664

Adjacent sequences: A066117 A066118 A066119 * A066121 A066122 A066123

Keyword

nonn,easy

Author

Henry Bottomley, Dec 05 2001

Status

approved