A031130 Number of proper factorizations of p1^n*p2^7, where p1 and p2 are distinct primes.

14, 44, 117, 256, 521, 974, 1751, 2997, 4986, 8042, 12692, 19583, 29718, 44323, 65209, 94641, 135804, 192698, 270821, 377047, 520623, 713122, 969783, 1309645, 1757446, 2343930, 3108552, 4100219

Offset

0,1

Links

Ray Chandler, Table of n, a(n) for n = 0..200

Formula

a(n) = A002756(n) - 1 = A028422(2^n*3^7). - Ray Chandler, May 01 2017

Crossrefs

Cf. A002756, A028422.

Sequence in context: A033587 A189807 A009942 * A215199 A216258 A064348

Adjacent sequences: A031127 A031128 A031129 * A031131 A031132 A031133

Keyword

nonn

Author

Jeff Burch

Extensions

Offset changed to 0 and more terms added by Ray Chandler, May 01 2017

Status

approved