login
Superduperprimorials: product of first n terms in Chernoff sequence.
12

%I #18 Jun 16 2018 18:36:33

%S 1,2,24,8640,653184000,114069441024000000,

%T 598216546007097937920000000000,

%U 1601591599167888308924824752807936000000000000000

%N Superduperprimorials: product of first n terms in Chernoff sequence.

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

%H Harry J. Smith, <a href="/A066120/b066120.txt">Table of n, a(n) for n = 0..17</a>

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

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

%o (PARI) { for (n=0, 17, a=1; for(i=1, n, a*=prime(i)^((n - i + 1)*(n - i + 2)/2)); write("b066120.txt", n, " ", a) ) } \\ _Harry J. Smith_, Feb 01 2010

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

%K nonn,easy

%O 0,2

%A _Henry Bottomley_, Dec 05 2001