login

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

A132398
Numbers n such that 11*n^2 + 1 is prime.
1
6, 24, 30, 54, 66, 84, 90, 96, 126, 144, 150, 186, 210, 234, 246, 276, 300, 324, 330, 360, 420, 426, 444, 450, 474, 480, 486, 516, 606, 624, 636, 684, 720, 750, 786, 804, 816, 864, 876, 900, 906, 924, 966, 996, 1014, 1020, 1056, 1074, 1104, 1110, 1116, 1194
OFFSET
1,1
COMMENTS
All terms are multiples of 6.
EXAMPLE
If n=6 then 11*n^2 + 1 = 397 (prime).
If n=144 then 11*n^2 + 1 = 228097 (prime).
MATHEMATICA
Select[Range[1300], PrimeQ[11*#^2 + 1] &] (* Stefan Steinerberger, Nov 13 2007 *)
PROG
(Magma) [ n: n in [0..1500] | IsPrime(11*n^2 + 1) ]; // Vincenzo Librandi, Jan 31 2011
(PARI) is(n)=isprime(11*n^2+1) \\ Charles R Greathouse IV, Jun 13 2017
CROSSREFS
Sequence in context: A334788 A332962 A350564 * A073120 A147778 A348714
KEYWORD
nonn,easy
AUTHOR
Parthasarathy Nambi, Nov 12 2007
EXTENSIONS
More terms from Stefan Steinerberger, Nov 13 2007
STATUS
approved