A293275 Exponent of highest power of 2 dividing the n-th (2,k)-perfect number A019278.

0, 1, 2, 3, 0, 4, 0, 3, 1, 2, 6, 2, 5, 3, 4, 4, 5, 3, 9, 6, 0, 6, 9, 2, 12, 9, 9, 4, 0, 9, 5, 8, 5, 1, 12, 6, 16, 12, 2, 7, 18, 8, 3, 4, 0, 10, 8, 5, 16, 2, 8, 16, 14, 10, 6, 1, 2, 8, 3, 18, 12, 8, 18, 11, 11, 4, 14, 9, 5, 10, 6, 11, 5, 5, 16, 7, 14, 12, 8, 13, 9, 18

Offset

1,3

Links

Michel Marcus, Table of n, a(n) for n = 1..130

Formula

a(n) = A007814(A019278(n)).

Prog

(PARI) lista(nn) = for (n=1, nn, if (denominator(sigma(sigma(n))/n) == 1, print1(valuation(n, 2), ", ")); ); \\ Michel Marcus, Oct 10 2017

Crossrefs

Cf. A007814, A019278, A205597 (when a(n) is zero).

Cf. A134665 (analog for multiperfect numbers).

Sequence in context: A324906 A164917 A166238 * A014197 A341825 A181308

Adjacent sequences: A293272 A293273 A293274 * A293276 A293277 A293278

Keyword

nonn

Author

Michel Marcus, Oct 10 2017

Status

approved