A264844 - OEIS

%I #12 Jul 02 2024 20:33:18

%S 191,1483,2281,5701,11971,14821,15581,21433,26183,39521,43283,54151,

%T 60041,61561,72733,81283,120233,135661,137941,166783,187531,220933,

%U 229711,244721,282683,292601,306091,323381,378101,409033,457711,461891,478801,513533,526871

%N Centered 19-gonal (or nonadecagonal) primes.

%C Primes of the form (19*k^2 - 19*k + 2)/2.

%H Robert Israel, <a href="/A264844/b264844.txt">Table of n, a(n) for n = 1..10000</a>

%H OEIS Wiki, <a href="https://oeis.org/wiki/Figurate_numbers">Figurate numbers</a>

%H Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/CenteredPolygonalNumber.html">Centered Polygonal Number</a>

%H Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/PrimeNumber.html">Prime Number</a>

%p select(isprime, [seq((19*k^2-19*k+2)/2,k=0..10^4)]); # _Robert Israel_, Jul 02 2024

%t Select[(19 #^2 - 19 # + 2)/2 &@ Range@ 250, PrimeQ] (* _Michael De Vlieger_, Nov 27 2015 *)

%o (PARI) for(n=1, 1e3, if(isprime(k=(19*n^2-19*n+2)/2), print1(k, ", "))) \\ _Altug Alkan_, Nov 26 2015

%Y Cf. A069132, A000040.

%K nonn

%O 1,1

%A _Ilya Gutkovskiy_, Nov 26 2015