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 A303026 #9 Aug 16 2018 08:51:36 %S A303026 1,8,16,32,64,76,128,152,212,256,304,424,512,524,608,722,848,1024, %T A303026 1048,1216,1244,1444,1532,1696,2014,2048,2096,2432,2488,2876,2888, %U A303026 3064,3392,3524,4028,4096,4192,4864,4976,4978,5204,5618,5752,5776,6128,6476,6784 %N A303026 Matula-Goebel numbers of series-reduced anti-binary (no unary or binary branchings) rooted trees. %e A303026 The sequence of series-reduced anti-binary rooted trees together with their Matula-Goebel numbers begins: %e A303026 1: o %e A303026 8: (ooo) %e A303026 16: (oooo) %e A303026 32: (ooooo) %e A303026 64: (oooooo) %e A303026 76: (oo(ooo)) %e A303026 128: (ooooooo) %e A303026 152: (ooo(ooo)) %e A303026 212: (oo(oooo)) %e A303026 256: (oooooooo) %e A303026 304: (oooo(ooo)) %e A303026 424: (ooo(oooo)) %e A303026 512: (ooooooooo) %e A303026 524: (oo(ooooo)) %e A303026 608: (ooooo(ooo)) %e A303026 722: (o(ooo)(ooo)) %e A303026 848: (oooo(oooo)) %e A303026 1024: (oooooooooo) %e A303026 1048: (ooo(ooooo)) %e A303026 1216: (oooooo(ooo)) %e A303026 1244: (oo(oooooo)) %e A303026 1444: (oo(ooo)(ooo)) %e A303026 1532: (oo(oo(ooo))) %e A303026 1696: (ooooo(oooo)) %e A303026 2014: (o(ooo)(oooo)) %e A303026 2048: (ooooooooooo) %t A303026 azQ[n_]:=Or[n==1,And[PrimeOmega[n]>2,And@@Cases[FactorInteger[n],{p_,_}:>azQ[PrimePi[p]]]]] %t A303026 Select[Range[1000],azQ] %Y A303026 Cf. A000081, A000598, A001190, A001678, A007097, A061775, A102403, A111299, A292050, A298422, A298424. %Y A303026 Cf. A303022, A303023, A303024, A303025, A303027. %K A303026 nonn %O A303026 1,2 %A A303026 _Gus Wiseman_, Aug 15 2018