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 A027177 #7 Oct 24 2019 19:14:11 %S A027177 1,3,10,19,42,76,156,283,570,1046,2096,3890,7784,14582,29168,55051, %T A027177 110106,209062,418128,797806,1595616,3056868,6113740,11752674, %U A027177 23505352,45316896,90633796,175175816,350351636,678639146,1357278296 %N A027177 a(n) = A027170(n, floor(n/2)). %K A027177 nonn %O A027177 0,2 %A A027177 _Clark Kimberling_