A031128 Number of proper factorizations of p1^n*p2^5, where p1 and p2 are distinct primes.

6, 18, 46, 96, 188, 338, 588, 974, 1575, 2471, 3803, 5726, 8497, 12399, 17873, 25432, 35817, 49907, 68938, 94377, 128233, 172916, 231629, 308239, 407803, 536411, 701909, 913772, 1184021, 1527164, 1961431, 2508761, 3196472

Offset: 0

Author

Jeff Burch

Keywords

• nonn

Crossrefs

Cf. A000491, A028422.

Formula

a(n) = A000491(n) - 1 = A028422(2^n*3^5). - Ray Chandler, May 01 2017

Extensions

Offset changed to 0, a(13)=12399 corrected and more terms added by Ray Chandler, May 01 2017