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 A147728 #5 Apr 07 2021 19:24:25 %S A147728 1,2,6,16,54,232,936,3880,17302,81584,409012,2138674,11754832, %T A147728 66857094,399774882,2469567300,15804526682 %N A147728 Number of permutations of 1..n with all sums of 2 through 6 adjacent terms respectively unique. %K A147728 nonn %O A147728 1,2 %A A147728 _R. H. Hardin_, Nov 11 2008