A260508 Numbers n such that A000203(n) == n*A001221(n).

6, 28, 120, 496, 672, 8128, 30240, 33550336, 8589869056, 137438691328

Offset

1,1

Comments

Subsequence of A007691.

a(n) is in A000396 iff A001221(a(n)) == 2, i.e., if a(n) is in A007774.

a(11) > 2.5*10^12. - Giovanni Resta, Jul 28 2015

Links

Table of n, a(n) for n=1..10.

Prog

(PARI) is(n) = sigma(n)==n*omega(n)

Crossrefs

Cf. A000396, A007691.

Sequence in context: A342924 A007691 A348031 * A334410 A065997 A348035

Adjacent sequences: A260505 A260506 A260507 * A260509 A260510 A260511

Keyword

nonn,more

Author

Felix Fröhlich, Jul 27 2015

Extensions

a(9)-a(10) from Giovanni Resta, Jul 28 2015

Status

approved