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 A378361 #8 Dec 10 2024 10:25:31 %S A378361 0,1,19,45,6413415,16068720 %N A378361 Octagonal indices of numbers that are both octagonal and octagonal pyramidal. %e A378361 19 is a term because the 19th octagonal number (1045) is also the 10th octagonal pyramidal number. %Y A378361 Cf. A000567 (octagonal numbers), A002414 (octagonal pyramidal numbers). %Y A378361 Cf. A344376. %K A378361 nonn,fini,full %O A378361 1,3 %A A378361 _Kelvin Voskuijl_, Nov 23 2024