1,2

Numbers n such that tau(n) = A000005(n) is not equal to 2*omega(n) = 2*A001221(n).

Table of n, a(n) for n=1..62.

Number 6 is not in the sequence because 6 = 2 * 3.

(MAGMA) [n: n in [1..1000] | NumberOfDivisors(n) ne 2*#PrimeDivisors(n)]

Complement of A167171.

Cf. A246716 (with two distinct primes), A008578 (with two distinct nonprimes), A289555 (with two distinct composites).

Sequence in context: A020671 A171598 A259241 * A013929 A162966 A190641

Adjacent sequences: A289550 A289551 A289552 * A289554 A289555 A289556

nonn

Jaroslav Krizek, Jul 07 2017

approved