A374217 The 3-adic valuation of sopfr(n), where sopfr is the sum of prime factors with repetition, A001414.

0, 1, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0, 2, 0, 0, 0, 0, 0, 2, 0, 0, 0, 2, 0, 1, 2, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 1, 0, 0, 0, 1, 0, 1, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 1, 0, 1, 2, 0, 0, 1, 0, 0, 0, 1, 0, 1, 0, 0, 2, 2, 0, 0, 1, 0, 0, 0, 0, 2, 0, 0, 0, 0, 0, 3, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 2, 0, 1, 0, 1, 0, 1, 0, 0, 1, 0, 0, 2

Offset

2,13

Links

Antti Karttunen, Table of n, a(n) for n = 2..100000

Formula

a(n) = A007949(A001414(n)).

Prog

(PARI)
A001414(n) = ((n=factor(n))[, 1]~*n[, 2]);
A374217(n) = valuation(A001414(n), 3);

Crossrefs

Cf. A001414, A007949, A289142 (gives the indices of nonzero terms here, after its initial 1), A373371

Cf. also A374207, A374216.

Sequence in context: A293814 A045837 A319687 * A126825 A045833 A117896

Adjacent sequences: A374214 A374215 A374216 * A374218 A374219 A374220

Keyword

nonn

Author

Antti Karttunen, Jul 02 2024

Status

approved