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A241028
Numbers n such that prime(n)^2 - 2*n is not prime.
1
5, 7, 8, 9, 11, 12, 13, 14, 17, 18, 20, 21, 23, 25, 26, 27, 29, 30, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 47, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 62, 63, 64, 65, 67, 68, 69, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85
OFFSET
1,1
LINKS
MATHEMATICA
Select[Range[100], !PrimeQ[Prime[#]^2 - 2 #] &]
PROG
(Magma) [n: n in [1..100] | not IsPrime(NthPrime(n)^2-2*n)];
CROSSREFS
Cf. A173473.
Sequence in context: A111339 A273786 A255922 * A171097 A166460 A118742
KEYWORD
nonn,easy
AUTHOR
Vincenzo Librandi, Apr 15 2014
STATUS
approved