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 A050875 #8 Aug 20 2021 05:47:27 %S A050875 33,45,51,63,128,131,133,137,145,152,155,157,161,164,167,173,181,185, %T A050875 188,191,193,194,199,203,211,217,218,223,227,229,230,239,247,251,253, %U A050875 254,514,516,519,520,523,525,528,531,533,537 %N A050875 Binary numbers d(1)...d(j) such that d(i) != d(j+1-i) for all but 6 values of i. %Y A050875 Cf. A050874. %K A050875 nonn,base %O A050875 1,1 %A A050875 _Clark Kimberling_ %E A050875 Name corrected by _Sean A. Irvine_, Aug 20 2021