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 A385616 #6 Jul 23 2025 16:14:40 %S A385616 0,1,39,85705,4026303,8886048529,417455130327,921323283480793, %T A385616 43282582818520431,95524640668969514017 %N A385616 Indices of pentagonal numbers that are one-fifth of another one. %Y A385616 Cf. A385152. %K A385616 nonn,more %O A385616 1,3 %A A385616 _Kelvin Voskuijl_, Jul 04 2025