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 A307493 #7 Feb 16 2025 08:33:55
%S A307493 16381,23199907725541,873105326726527441,169377932722437899461,
%T A307493 532026300937919058017204151243671297356368598920355705257429996547710782877327451810988538831181
%N A307493 Primes that are both centered triangular and centered square.
%C A307493 Primes that are the sum of three consecutive triangular numbers and the sum of two consecutive squares.
%C A307493 The next term is too large to include.
%H A307493 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/CenteredTriangularNumber.html">Centered Triangular Number</a>
%H A307493 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/CenteredSquareNumber.html">Centered Square Number</a>
%t A307493 Select[LinearRecurrence[{195, -195, 1}, {1, 85, 16381}, 43], PrimeQ[#] &]
%Y A307493 Intersection of A027862 and A125602.
%Y A307493 Cf. A000040, A001110, A001844, A005448, A131750, A163251, A269414.
%K A307493 nonn
%O A307493 1,1
%A A307493 _Ilya Gutkovskiy_, Apr 10 2019