A278779 Numbers n such that A000041(n) is of the form 2^2 * k for odd k.

26, 30, 55, 58, 59, 62, 74, 78, 80, 84, 100, 108, 112, 113, 117, 124, 126, 135, 153, 187, 191, 200, 205, 258, 265, 280, 291, 310, 317, 323, 336, 337, 342, 344, 351, 352, 353, 358, 359, 365, 374, 380, 384, 404, 409, 416, 444, 445, 458, 481, 485, 492, 501, 503

Offset

1,1

Comments

Numbers n such that A278478(n) = 2.

Also numbers n such that A000041(n) has twice as many even divisors as odd divisors.

Links

Colin Barker, Table of n, a(n) for n = 1..1000

Formula

A000041(a(n)) = A278196(n).

Prog

(PARI) isok(n) = valuation(numbpart(n), 2)==2;
select(n->isok(n), vector(1000, n, n))

Crossrefs

Cf. A000041, A278196, A278780, A278781, A278782, A278783, A278784.

Positions of 2's in A278478.

Sequence in context: A303815 A069962 A178098 * A045163 A282110 A275192

Adjacent sequences: A278776 A278777 A278778 * A278780 A278781 A278782

Keyword

nonn

Author

Colin Barker, Nov 28 2016

Status

approved