OFFSET
1,1
COMMENTS
Primes of the form (19*k^2 - 19*k + 2)/2.
LINKS
Robert Israel, Table of n, a(n) for n = 1..10000
OEIS Wiki, Figurate numbers
Eric Weisstein's World of Mathematics, Centered Polygonal Number
Eric Weisstein's World of Mathematics, Prime Number
MAPLE
select(isprime, [seq((19*k^2-19*k+2)/2, k=0..10^4)]); # Robert Israel, Jul 02 2024
MATHEMATICA
Select[(19 #^2 - 19 # + 2)/2 &@ Range@ 250, PrimeQ] (* Michael De Vlieger, Nov 27 2015 *)
PROG
(PARI) for(n=1, 1e3, if(isprime(k=(19*n^2-19*n+2)/2), print1(k, ", "))) \\ Altug Alkan, Nov 26 2015
CROSSREFS
KEYWORD
nonn
AUTHOR
Ilya Gutkovskiy, Nov 26 2015
STATUS
approved