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A374217
The 3-adic valuation of sopfr(n), where sopfr is the sum of prime factors with repetition, A001414.
2
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
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
KEYWORD
nonn
AUTHOR
Antti Karttunen, Jul 02 2024
STATUS
approved