A033635 Square-root-perfect numbers: srsigma(n)=m*n^(1/2) for some integer m.

4, 64, 48400, 37822470400, 6935904849126400, 11883371958374400, 62796991981158400, 87762493613171048488960000, 874812594495483490385610887270400000000000000

Offset

0,1

Links

Table of n, a(n) for n=0..8.

Formula

If n = Product p(i)^r(i) then srsigma(n) = Product [ (p(i)^(r(i)/2+1/2)-1)/(p(i)^(1/2)-1) ].

Crossrefs

Sequence in context: A120581 A146520 A030176 * A138835 A234608 A119601

Adjacent sequences: A033632 A033633 A033634 * A033636 A033637 A033638

Keyword

nonn

Author

Yasutoshi Kohmoto

Status

approved