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A290089
Filter-sequence for the prime signature of cototient: a(1) = 0; for n > 1, a(n) = A101296(A051953(n)).
2
0, 1, 1, 2, 1, 3, 1, 3, 2, 4, 1, 5, 1, 5, 2, 5, 1, 6, 1, 6, 3, 6, 1, 7, 2, 4, 3, 7, 1, 4, 1, 7, 2, 6, 2, 8, 1, 6, 4, 8, 1, 9, 1, 8, 4, 8, 1, 10, 2, 9, 2, 6, 1, 11, 4, 10, 4, 9, 1, 6, 1, 10, 5, 10, 2, 4, 1, 11, 3, 4, 1, 12, 1, 4, 4, 8, 2, 8, 1, 12, 5, 9, 1, 13, 4, 6, 2, 12, 1, 9, 2, 12, 4, 12, 2, 14, 1, 8, 4, 13, 1, 9, 1, 8, 4
OFFSET
1,4
LINKS
FORMULA
a(1) = 0; for n > 1, a(n) = A101296(A051953(n)).
CROSSREFS
Cf. A000040 (the positions of 1's), A050530 (the positions of 2's).
Sequence in context: A020650 A361373 A124224 * A323902 A331991 A351465
KEYWORD
nonn
AUTHOR
Antti Karttunen, Aug 07 2017
STATUS
approved