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A136242
Numbers k among A008864 such that k^2 - k + 1 is prime.
3
3, 4, 6, 18, 42, 60, 72, 90, 102, 132, 168, 174, 294, 384, 678, 702, 744, 762, 774, 828, 840, 858, 912, 1092, 1098, 1164, 1182, 1194, 1218, 1374, 1428, 1488, 1560, 1584, 1710, 1812, 1848, 1932, 1974, 2130, 2274, 2310, 2340, 2412, 2664, 2730, 2790, 2958
OFFSET
1,1
COMMENTS
See A053183 for the primes associated with a(n).
LINKS
FORMULA
a(n) = A053182(n) + 1.
MATHEMATICA
Select[Prime[Range[500]] + 1, PrimeQ[#^2 - # + 1] &] (* Amiram Eldar, Apr 19 2024 *)
PROG
(PARI) lista(pmax) = forprime(p=1, pmax, if(isprime(p^2+p+1), print1(p+1, ", "))); \\ Amiram Eldar, Apr 19 2024
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Lekraj Beedassy, Dec 24 2007
STATUS
approved