A286357 - OEIS

A286357

One more than the exponent of the highest power of 2 dividing sigma(n): a(n) = A001511(A000203(n)).

1, 1, 3, 1, 2, 3, 4, 1, 1, 2, 3, 3, 2, 4, 4, 1, 2, 1, 3, 2, 6, 3, 4, 3, 1, 2, 4, 4, 2, 4, 6, 1, 5, 2, 5, 1, 2, 3, 4, 2, 2, 6, 3, 3, 2, 4, 5, 3, 1, 1, 4, 2, 2, 4, 4, 4, 5, 2, 3, 4, 2, 6, 4, 1, 3, 5, 3, 2, 6, 5, 4, 1, 2, 2, 3, 3, 6, 4, 5, 2, 1, 2, 3, 6, 3, 3, 4, 3, 2, 2, 5, 4, 8, 5, 4, 3, 2, 1, 3, 1, 2, 4, 4, 2, 7, 2, 3, 4, 2, 4, 4, 4, 2, 5, 5, 2, 2, 3, 5, 4

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OFFSET

1,3

LINKS

Antti Karttunen, Table of n, a(n) for n = 1..10000

Index entries for sequences related to sigma(n)

FORMULA

a(n) = A001511(A000203(n)).

a(n) = 1 + A000523(A000203(n)/A161942(n)). [See also A082903.]

a(n) = 1 iff A053866(n) = 1.

MATHEMATICA

Table[IntegerExponent[DivisorSigma[1, n], 2]+1, {n, 120}] (* Harvey P. Dale, Sep 04 2023 *)