A108466 Number of factorizations of (n,n) into pairs (i,j) with i,j>1.

1, 1, 1, 2, 1, 3, 1, 4, 2, 3, 1, 11, 1, 3, 3, 9, 1, 11, 1, 11, 3, 3, 1, 35, 2, 3, 4, 11, 1, 25, 1, 20, 3, 3, 3, 55, 1, 3, 3, 35, 1, 25, 1, 11, 11, 3, 1, 106, 2, 11, 3, 11, 1, 35, 3, 35, 3, 3, 1, 132, 1, 3, 11, 45, 3, 25, 1, 11, 3, 25, 1, 222, 1, 3, 11, 11, 3, 25, 1, 106, 9, 3, 1, 132, 3, 3

Offset

1,4

Comments

(a,b)*(x,y)=(a*x,b*y).

a(n) depends only on prime signature of n (cf. A025487). So a(24) = a(375) since 24=2^3*3 and 375=3*5^3 both have prime signature (3,1).

Links

Table of n, a(n) for n=1..86.

Crossrefs

Cf. A108461. Main diagonal of A108465. a(A025487)=A108467. a(p^k)=A108469(k). a(A002110)=A023997.

Sequence in context: A074206 A173801 A368198 * A211110 A325828 A200780

Adjacent sequences: A108463 A108464 A108465 * A108467 A108468 A108469

Keyword

nonn

Author

Christian G. Bower, Jun 03 2005

Status

approved