A174898 a(n) = characteristic function of numbers k such that A007955(m) = k has no solution for any m, where A007955(m) = product of divisors of m.

0, 0, 0, 1, 0, 1, 0, 0, 1, 1, 0, 1, 0, 1, 1, 1, 0, 1, 0, 1, 1, 1, 0, 1, 1, 1, 0, 1, 0, 1, 0, 1, 1, 1, 1, 0, 0, 1, 1, 1, 0, 1, 0, 1, 1, 1, 0, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1, 0, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 1, 0, 1, 0, 1, 1, 1, 1, 1, 0, 1, 1, 1, 0, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1, 1, 1, 0, 1, 1, 0, 0, 1, 0, 1, 1

Offset: 1

Author

Jaroslav Krizek, Apr 01 2010

Keywords

• nonn

Comments

a(n) = characteristic function of numbers from A174896(n).

a(n) = 1 if A007955(m) not equal to n for any m, else 0.

Links

• Antti Karttunen, Table of n, a(n) for n = 1..20000 (computed from the b-file of A174897)
• Index entries for characteristic functions

Crossrefs

Cf. A007955, A174896, A174897.

Formula

a(n) = 1 - A174897(n).

Extensions

More terms from Antti Karttunen, Oct 20 2017