A099585 Remove all 3s from prime(n) - 1.

1, 2, 4, 2, 10, 4, 16, 2, 22, 28, 10, 4, 40, 14, 46, 52, 58, 20, 22, 70, 8, 26, 82, 88, 32, 100, 34, 106, 4, 112, 14, 130, 136, 46, 148, 50, 52, 2, 166, 172, 178, 20, 190, 64, 196, 22, 70, 74, 226, 76, 232, 238, 80, 250, 256, 262, 268, 10, 92, 280, 94, 292, 34, 310

Offset: 1

Author

Ralf Stephan, Oct 24 2004

Keywords

• nonn

Crossrefs

Equals A038502( A006093(n) ). prime(n)-1 = a(n) * 3^A099584(n).

Cf. A057023.

Programs

PARI

a(n) = (prime(n)-1)/3^valuation(prime(n)-1,3)