A264821 Centered 14-gonal (or tetradecagonal) primes.

43, 211, 631, 1093, 1471, 2143, 4201, 6091, 7393, 8821, 17851, 23143, 24781, 25621, 33811, 36793, 38851, 39901, 42043, 45361, 53593, 57331, 63841, 76441, 91771, 96643, 99961, 101641, 110251, 126631, 128521, 138181, 146161, 152293, 158551, 184843, 189421, 220543

Offset: 1

Author

Ilya Gutkovskiy, Nov 26 2015

Keywords

• nonn

Comments

Primes of the form 7*k^2 - 7*k + 1.

Links

• OEIS Wiki, Figurate numbers
• Eric Weisstein's World of Mathematics, Centered Polygonal Number
• Eric Weisstein's World of Mathematics, Prime Number

Crossrefs

Cf. A069127, A000040.

Programs

Mathematica

Select[Table[7n^2-7n+1,{n,200}],PrimeQ] (* Harvey P. Dale, Jul 27 2021 *)

PARI

for(n=1, 1e3, if(isprime(k=7*n^2-7*n+1), print1(k,", "))) \\ Altug Alkan, Nov 26 2015