

A154619


Primes of the form (4k^2 + 4k  5)/5.


1



23, 71, 167, 191, 479, 743, 1583, 2039, 2927, 3863, 5711, 6551, 7919, 9767, 10487, 11423, 15791, 16703, 18119, 21647, 21911, 24359, 27527, 32159, 35111, 35447, 38543, 43991, 45887, 46271, 52223, 54287, 55967, 60719, 67511, 69383, 76631
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OFFSET

1,1


COMMENTS

The numbers k that generate integers of the form (4k^2 + 4k  5)/5 are in A047208. The primes are generated by the subset k = 5, 9, 14, 15, 24, 30, ... of these.  R. J. Mathar, Jan 25 2009


LINKS



MAPLE

a := proc (n) if type((4/5)*n^2+(4/5)*n1, integer) = true and isprime((4/5)*n^2+(4/5)*n1) = true then (4/5)*n^2+(4/5)*n1 else end if end proc: seq(a(n), n = 1 .. 340); # Emeric Deutsch, Jan 21 2009


MATHEMATICA

Select[Table[(4n^2+4n5)/5, {n, 3, 200}], PrimeQ] (* Vincenzo Librandi, Jul 23 2012 *)


CROSSREFS



KEYWORD

nonn,easy


AUTHOR



EXTENSIONS



STATUS

approved



