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A266963
Numbers n such that (2^(n+7)*5^(n+6)-1024877)/9 is prime (n > 0).
0
1, 27, 37, 42, 94, 117, 667, 1413, 1764, 4138, 8341, 9337, 10737, 16132, 17425
OFFSET
1,2
COMMENTS
Numbers n such that '108347' (prime) appended to n times the digit 2 is prime.
a(n) mod 3 <= 1.
EXAMPLE
1 appears because 2108347 ('2' prepended to '108347') is prime.
MATHEMATICA
Select[ Range[2000], PrimeQ[(2^(#+7) * 5^(#+6) - 1024877) / 9] &] (*Or*)
Select[ Range[2000], PrimeQ[5*(2^(#+7) * 5^(#+5) - 204979) / 9 + 2] &]
PROG
(Magma) [n: n in [1..700] |IsPrime((2^(n+7)*5^(n+6)-1024877) div 9)]; // Vincenzo Librandi, Jan 13 2016
(PARI) is(n) = ispseudoprime((2^(n+7)*5^(n+6) - 1024877) / 9); \\ Altug Alkan, Jan 15 2016
CROSSREFS
Sequence in context: A152053 A166649 A025145 * A180961 A278643 A069105
KEYWORD
nonn,base,more
AUTHOR
Mikk Heidemaa, Jan 07 2016
STATUS
approved