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 A339493 #9 Dec 08 2020 02:31:31 %S A339493 0,0,4,11,24,52,110,228,467,949,1916,3848,7696,15342,30505,60527, %T A339493 119892,237156,468590,925032,1824727,3597289,7088216,13961168, %U A339493 27489168,54110618,106489245,209531251,412217072,810865812,1594878078,3136673996,6168522827,12130206941 %N A339493 a(n) = A333650(n, 3) for n >= 3; a(1) = a(2) = 0. %Y A339493 Cf. A333650, A339494. %K A339493 nonn %O A339493 1,3 %A A339493 _Peter Luschny_, Dec 07 2020