A290089 Filter-sequence for the prime signature of cototient: a(1) = 0; for n > 1, a(n) = A101296(A051953(n)).

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

Author

Antti Karttunen, Aug 07 2017

Keywords

• nonn

Links

• Antti Karttunen, Table of n, a(n) for n = 1..16384

Crossrefs

Cf. A051953, A101296, A277906, A290087.

Cf. A000040 (the positions of 1's), A050530 (the positions of 2's).

Formula

a(1) = 0; for n > 1, a(n) = A101296(A051953(n)).