A078330 - OEIS

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A078330

Primes p such that mu(p-1) = -1, where mu is the Moebius function; that is, p-1 is squarefree and has an odd number of prime factors.

3, 31, 43, 67, 71, 79, 103, 131, 139, 191, 223, 239, 283, 311, 367, 419, 431, 439, 443, 499, 599, 607, 619, 643, 647, 659, 683, 743, 787, 823, 827, 907, 947, 971, 1031, 1039, 1087, 1091, 1103, 1163, 1223, 1259, 1399, 1427, 1447, 1499, 1511, 1543, 1559, 1571

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OFFSET

1,1

LINKS

Amiram Eldar, Table of n, a(n) for n = 1..10000

Eric Weisstein's World of Mathematics, Moebius Function.

EXAMPLE

31 is in the sequence because 31 is a prime and mu(30) = -1.

37 is not in the sequence because, although 37 is prime, mu(36) = 0.

MATHEMATICA

Select[Prime[Range[400]], MoebiusMu[# - 1] == -1 &] (* from T. D. Noe *)

PROG