A385890 Positions of first appearances in A245563 = run lengths of binary indices.

1, 2, 4, 6, 8, 12, 14, 16, 22, 24, 28, 30, 32, 44, 46, 48, 54, 56, 60, 62, 64, 86, 88, 92, 94, 96, 108, 110, 112, 118, 120, 124, 126, 128, 172, 174, 176, 182, 184, 188, 190, 192, 214, 216, 220, 222, 224, 236, 238, 240, 246, 248, 252, 254, 256, 342, 344, 348

Offset

1,2

Comments

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.

Links

Table of n, a(n) for n=1..58.

Mathematica

bpe[n_]:=Join@@Position[Reverse[IntegerDigits[n, 2]], 1];
q=Table[Length/@Split[bpe[n], #2==#1+1&], {n, 0, 1000}];
Select[Range[Length[q]-1], !MemberQ[Take[q, #-1], q[[#]]]&]

Crossrefs

These are positions of firsts appearances in A245563, ranks A385889, reverse A245562.

A384175 counts subsets with all distinct lengths of maximal runs, complement A384176.

A384877 lists anti-run lengths of binary indices, ranks A385816.

Cf. A000120, A023758, A048793, A069010, A200649, A243815, A246029, A328592, A384890.

Sequence in context: A015929 A331994 A043723 * A376508 A331681 A006998

Adjacent sequences: A385887 A385888 A385889 * A385891 A385892 A385893

Keyword

nonn

Author

Gus Wiseman, Jul 18 2025

Status

approved