A121820 Numbers m such that greatest prime divisor of (m-th prime + 1) is 3.

1, 3, 5, 7, 9, 15, 16, 20, 28, 43, 76, 83, 118, 150, 164, 190, 377, 597, 801, 889, 1091, 1561, 1814, 2601, 3016, 6253, 7281, 13005, 15167, 25607, 27191, 37126, 39419, 41357, 62946, 78155, 83024, 184383, 702826, 1146234, 1203569, 1595690, 1871469

Offset: 1

Author

Zak Seidov, Sep 09 2006

Keywords

• nonn

Comments

Or, position of 3 in A023509 Greatest prime divisor of n-th prime + 1.

Crossrefs

Cf. A023509.

Programs

Mathematica

Select[Range[990000],FactorInteger[Prime[ # ]+1][[ -1,1]]==3&]

Extensions

More terms from Stefan Steinerberger, May 18 2007