A201790 Primes of the form 5n^2 - 9.

11, 71, 311, 491, 971, 2411, 3371, 3911, 7211, 12491, 15671, 16811, 19211, 28871, 31991, 38711, 44171, 49991, 56171, 67271, 74411, 76871, 100811, 118571, 134471, 137771, 154871, 165611, 176711, 180491, 188171, 224711, 250871, 255371

Offset

1,1

Links

Vincenzo Librandi, Table of n, a(n) for n = 1..5000

Mathematica

 Select[Table[5n^2-9, {n, 2, 1000}], PrimeQ]

Prog

(Magma) [a: n in [2..500] | IsPrime(a) where a is 5*n^2-9];

Crossrefs

Sequence in context: A139850 A233416 A174822 * A268985 A211386 A049350

Adjacent sequences: A201787 A201788 A201789 * A201791 A201792 A201793

Keyword

nonn,easy

Author

Vincenzo Librandi, Dec 05 2011

Status

approved