A121820 - OEIS

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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

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OFFSET

1,2

COMMENTS

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

LINKS

Table of n, a(n) for n=1..43.

MATHEMATICA

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

CROSSREFS

Cf. A023509.

Sequence in context: A349130 A357148 A268496 * A357150 A351462 A258159

Adjacent sequences: A121817 A121818 A121819 * A121821 A121822 A121823

KEYWORD

nonn

AUTHOR

Zak Seidov, Sep 09 2006

EXTENSIONS

More terms from Stefan Steinerberger, May 18 2007

STATUS

approved