A182799 Positions of primes in A167171.

1, 2, 3, 5, 7, 8, 11, 12, 15, 17, 18, 22, 25, 26, 28, 30, 34, 35, 38, 40, 41, 44, 46, 50, 55, 56, 57, 59, 60, 62, 68, 70, 73, 74, 80, 81, 83, 87, 89, 90, 93, 94, 98, 99, 101, 102, 109, 117, 119, 120, 121, 124, 125, 128, 131, 134, 137, 138, 140, 142

Offset: 1

Author

Clark Kimberling, Dec 03 2010

Keywords

• nonn

Comments

Complement of A182800.

Examples

			A167171=(2,3,5,6,7,10,11,13,14,15,17,19,21,22,23,...)  consists of primes and products p*q of distinct primes.
a(1)=1 because 2 is in position 1;
a(4)=5 because 7 is in position 5.
		

Crossrefs

Cf. A000040, A167171, A182800.

Programs

PARI

lista(nn) = {nb = 0; for (n=1, nn, if (numdiv(n) == 2*omega(n), nb++; if (isprime(n), print1(nb, ", "));););} \\ Michel Marcus, May 15 2017