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A182799
Positions of primes in A167171.
1
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
1,2
COMMENTS
Complement of A182800.
EXAMPLE
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.
PROG
(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
CROSSREFS
KEYWORD
nonn
AUTHOR
Clark Kimberling, Dec 03 2010
STATUS
approved