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 A137400 #3 Jul 25 2018 21:12:26 %S A137400 6,30,140,631,2786,12136,52368,224406,956516,4060038,17175132, %T A137400 72454075,304941386,1280898304,5371301504,22491017758,94055344244, %U A137400 392888085100,1639534704632,6835739258998,28477594607348,118551827347576 %N A137400 a(n) = A128941(n) + 2. %Y A137400 Cf. A128941. %K A137400 nonn %O A137400 0,1 %A A137400 Lyle Ramshaw (lyle.ramshaw(AT)hp.com), Apr 08 2008