A046295 Numbers k such that 2^k contains 2^9=512 as its largest proper substring of the form 2^m.

109, 135, 192, 209, 221, 223, 231, 241, 259, 266, 277, 283, 285, 293, 302, 305, 309, 314, 323, 333, 344, 345, 359, 382, 387, 400, 402, 407, 409, 413, 415, 421, 431, 443, 451, 472, 476, 485, 501, 509, 526, 529, 537, 540, 548, 551, 556, 561, 566, 573, 574

Offset

1,1

Links

Table of n, a(n) for n=1..51.

Example

2^135 = 435561429658801233233119497{512}66331066368.

Mathematica

sub2[n_] := Block[{s = ToString[2^n], k = n - 1}, While[k >= 0 && ! StringContainsQ[s, ToString[2^k]], k--]; k]; Select[Range[574], sub2[#] == 9 &] (* Giovanni Resta, Oct 14 2019 *)

Crossrefs

Cf. A033921.

Sequence in context: A039492 A253155 A095609 * A164288 A325074 A182476

Adjacent sequences: A046292 A046293 A046294 * A046296 A046297 A046298

Keyword

nonn,base

Author

Patrick De Geest, Jun 15 1998

Status

approved