0,3

It appears that a(n)>0 for all n. With the exception of n=2, a(n)=1 when n is p-1, where p is a Mersenne prime (A000043). Flammenkamp has an attractive graph of this sequence, including n for which there is incomplete data.

Table of n, a(n) for n=0..81.

Achim Flammenkamp, The Multiply Perfect Numbers Page

a(2)=2 because only 28 and 2178540 have 2^2 as their highest power of 2.

Cf. A134665 (highest power of 2 for each MPN).

Sequence in context: A174714 A116633 A263232 * A129712 A051720 A022693

Adjacent sequences: A134663 A134664 A134665 * A134667 A134668 A134669

nonn

T. D. Noe, Nov 05 2007

approved