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 A385890 #7 Jul 18 2025 18:21:08
%S A385890 1,2,4,6,8,12,14,16,22,24,28,30,32,44,46,48,54,56,60,62,64,86,88,92,
%T A385890 94,96,108,110,112,118,120,124,126,128,172,174,176,182,184,188,190,
%U A385890 192,214,216,220,222,224,236,238,240,246,248,252,254,256,342,344,348
%N A385890 Positions of first appearances in A245563 = run lengths of binary indices.
%C A385890 A binary index of n is any position of a 1 in its reversed binary expansion. The binary indices of n are row n of A048793.
%t A385890 bpe[n_]:=Join@@Position[Reverse[IntegerDigits[n,2]],1];
%t A385890 q=Table[Length/@Split[bpe[n],#2==#1+1&],{n,0,1000}];
%t A385890 Select[Range[Length[q]-1],!MemberQ[Take[q,#-1],q[[#]]]&]
%Y A385890 These are positions of firsts appearances in A245563, ranks A385889, reverse A245562.
%Y A385890 A384175 counts subsets with all distinct lengths of maximal runs, complement A384176.
%Y A385890 A384877 lists anti-run lengths of binary indices, ranks A385816.
%Y A385890 Cf. A000120, A023758, A048793, A069010, A200649, A243815, A246029, A328592, A384890.
%K A385890 nonn
%O A385890 1,2
%A A385890 _Gus Wiseman_, Jul 18 2025