A167277 - OEIS

A167277

Largest nonprime<n-th single (or isolated or non-twin) prime.

1, 22, 36, 46, 52, 66, 78, 82, 88, 96, 112, 126, 130, 156, 162, 166, 172, 210, 222, 232, 250, 256, 262, 276, 292, 306, 316, 330, 336, 352, 358, 366, 372, 378, 382, 388, 396, 400, 408, 438, 442, 448, 456, 466, 478, 486, 490, 498, 502, 508, 540, 546, 556, 562

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,2

COMMENTS

Or, n-th single prime minus smallest divisor of n-th single prime.

LINKS

Harvey P. Dale, Table of n, a(n) for n = 1..2500

FORMULA

a(n) = A007510(n) - 1

MATHEMATICA

Select[Prime[Range[150]], NoneTrue[#+{2, -2}, PrimeQ]&]-1 (* Harvey P. Dale, Dec 26 2022 *)

CROSSREFS