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 A306574 #12 Feb 25 2019 20:41:45 %S A306574 2,3,4,4,5,4,5,6,4,5,6,5,7,5,5,6,6,7,6,6,8,6,6,6 %N A306574 Incorrect version of A088527. %C A306574 Claimed to be the maximum k such that n is the k-th term in some Fibonacci-type sequence. %H A306574 Tamás Dénes, <a href="https://doi.org/10.1016/S0012-365X(03)00207-3">Problem 413. Fibonacci index of natural numbers</a>, Research problems / Discrete Mathematics 272 (2003) 301-306 (but there are several errors in the table given there). %Y A306574 Incorrect version of A088527. %K A306574 dead %O A306574 1,1