1,1

The complement of A076361, that is, the indices k where A076360(k) is not zero.

Table of n, a(n) for n=1..72.

a(6)= 8 is in the list because tau(sigma(8))=A062068(8)=4 whereas sigma(tau(8)) = A062069(8) = 7.

(PARI) is(n)=numdiv(sigma(n))!=sigma(numdiv(n)) \\ Charles R Greathouse IV, Jun 25 2013

Cf. A000005, A000203, A076361, A076360.

Sequence in context: A004722 A094798 A326178 * A083792 A083794 A133016

Adjacent sequences: A162877 A162878 A162879 * A162881 A162882 A162883

nonn

Jaroslav Krizek, Jul 16 2009

Edited by R. J. Mathar, Jul 21 2009

approved