A108463 a(n) = A108462(A025487(n)).

1, 2, 9, 15, 31, 92, 109, 444, 203, 339, 712, 1903, 1663, 1043, 4070, 7279, 10105, 2998, 20061, 16601, 25904, 4140, 27036, 51551, 8406, 86713, 117750, 86172, 43263, 149570, 229964, 22652, 342999, 682147, 272252, 318223, 717296, 198091, 930988

Offset

1,2

Comments

Number of factorizations of (k,k) into pairs (i,j) by prime signature.

Pairs (i,j) must satisfy i,j>=1, not both 1; (a,b)*(x,y) = (a*x,b*y).

Links

Table of n, a(n) for n=1..39.

Crossrefs

Cf. A025487, A108462.

Sequence in context: A319967 A063094 A369154 * A056724 A295732 A083174

Adjacent sequences: A108460 A108461 A108462 * A108464 A108465 A108466

Keyword

nonn,more

Author

Christian G. Bower, Jun 03 2005

Extensions

Offset changed to 1 and a(27)-a(29) from Jinyuan Wang, Jan 17 2022

a(30)-a(39) from Amiram Eldar, Mar 04 2023

Status

approved