A171447 - OEIS

A171447

Numbers n such that n+1 is prime, and (n+1)^3-n^3 is prime.

1, 2, 4, 6, 10, 28, 30, 42, 52, 58, 66, 88, 108, 136, 156, 172, 196, 238, 312, 346, 352, 388, 448, 520, 546, 556, 570, 576, 598, 612, 646, 676, 732, 742, 786, 856, 906, 940, 976, 1050, 1068, 1092, 1152, 1192, 1222, 1228, 1236, 1302, 1432, 1452, 1458, 1480

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

OFFSET

1,2

LINKS

Vincenzo Librandi, Table of n, a(n) for n = 1..1000

FORMULA

a(n) = A165682(n)-1. - R. J. Mathar, Jan 04 2011

EXAMPLE

for n=10, 10+1=11 and 11^3-10^3=331; n=28, 28+1=29 and 29^3-28^3=2437

MATHEMATICA

Select[Range[1500], PrimeQ[# + 1]&&PrimeQ[(# + 1)^3 - #^3]&] (* Vincenzo Librandi, Apr 05 2013 *)

PROG