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 A355276 #13 Sep 11 2022 00:28:08 %S A355276 2,2,1,4,4,6,3,8,9,12,11,18,33,37,40,43,64,77,71,118,135,167,241 %N A355276 Number of n-digit terms in A347475. %Y A355276 Cf. A000217 (triangular numbers), A014261 (numbers with only odd digits), A117960 (triangular numbers with only odd digits), A349243 (indices of the former), A347475 (such indices with only odd digits), A349247 (least such k-digit term), A355277 (largest such k-digit term). %K A355276 nonn,base,more %O A355276 1,1 %A A355276 _M. F. Hasler_, Sep 08 2022 %E A355276 a(20)-a(23) from _Michael S. Branicky_, Sep 09 2022