This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A145838 #9 Feb 16 2025 08:33:09
%S A145838 31,181,331,601,1051,1381,3331,4951,5641,5881,9151,11731,12781,14251,
%T A145838 17431,17851,19141,21391,31081,33931,41281,43891,51481,52201,61231,
%U A145838 63601,67651,70141,70981,84181,92641,100501,104551,107641,116101,126001
%N A145838 Primes in A005891 = Centered pentagonal numbers: (5n^2 + 5n + 2)/2.
%H A145838 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/CenteredPentagonalNumber.html">Centerd Pentagonal Number</a>
%p A145838 A005891 := proc(n) (5*n*(n+1)+2)/2 ; end: for n from 1 to 1000 do c := A005891(n) ; if isprime(c) then printf("%d,",c) ; fi; od: # _R. J. Mathar_, Nov 02 2008
%Y A145838 Cf. A005891 = Centered pentagonal numbers: (5n^2 + 5n + 2)/2.
%K A145838 nonn
%O A145838 1,1
%A A145838 _Alexander Adamchuk_, Oct 21 2008
%E A145838 More terms from _R. J. Mathar_, Nov 02 2008