

A166475


4th level primorials: product of first n superduperprimorials.


7




OFFSET

0,2


COMMENTS

Next term has 110 digits.
a(n) = first counting number with n distinct positive tetrahedral exponents in its prime factorization (cf. A000292).
Note: a(n) is not the first counting number with n distinct square exponents in its prime factorization, as previously stated. That sequence is A212170.  Matthew Vandermast, May 23 2012


LINKS

Table of n, a(n) for n=0..6.
D. Alpern, Factorization using the Elliptic Curve Method


FORMULA

a(n) = Product_{k=1..n} prime(k)^((nk+1)^2).


EXAMPLE

a(3) = 414720 = 2^10*3^4*5^1 has 3 positive tetrahedral exponents in its prime factorization (cf. A000292). It is the smallest number with this property.


CROSSREFS

Subsequence of A025487.
Cf. A002110, A006939, A066120 for first, second and third level primorials.
Sequence in context: A191954 A212170 A057527 * A152688 A046873 A261125
Adjacent sequences: A166472 A166473 A166474 * A166476 A166477 A166478


KEYWORD

nonn,easy


AUTHOR

Matthew Vandermast, Nov 05 2009


EXTENSIONS

Offset corrected by Matthew Vandermast, Nov 07 2009
Edited by Matthew Vandermast, Nov 10 2009, May 23 2012
Name changed by Arkadiusz Wesolowski, Feb 21 2014


STATUS

approved



