OFFSET
1,1
COMMENTS
Primes of the form 10*k^2 - 10*k + 1.
LINKS
OEIS Wiki, Figurate numbers
Eric Weisstein's World of Mathematics, Centered Polygonal Number
Eric Weisstein's World of Mathematics, Prime Number
MATHEMATICA
Select[Table[10 n^2 - 10 n + 1, {n, 200}], PrimeQ] (* Vincenzo Librandi, Nov 27 2015 *)
PROG
(PARI) for(n=1, 1e3, if(isprime(k=10*n^2-10*n+1), print1(k, ", "))) \\ Altug Alkan, Nov 26 2015
CROSSREFS
KEYWORD
nonn
AUTHOR
Ilya Gutkovskiy, Nov 26 2015
STATUS
approved