A031125 - OEIS

The OEIS is supported by the many generous donors to the OEIS Foundation.

A031125

Number of proper factorizations of p1^n*p2^2, where p1 and p2 are distinct primes.

1

1, 3, 8, 15, 28, 46, 76, 117, 180, 266, 391, 559, 796, 1110, 1540, 2105, 2862, 3845, 5141, 6807, 8972, 11732, 15274, 19752, 25442, 32581, 41568, 52769, 66756, 84077, 105554, 131994, 164565, 204449, 253291, 312798, 385284, 473182, 579721, 708352

(list; graph; refs; listen; history; text; internal format)

OFFSET

0,2

LINKS

Ray Chandler, Table of n, a(n) for n = 0..10000

FORMULA

a(n) = A000291(n) - 1 = A028422(2^n*3^2). - Ray Chandler, May 01 2017

CROSSREFS

Cf. A000291, A028422.

Sequence in context: A047873 A036419 A054107 * A294423 A294426 A097589

Adjacent sequences: A031122 A031123 A031124 * A031126 A031127 A031128

KEYWORD

nonn

AUTHOR

EXTENSIONS

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

STATUS

approved