A046292 Numbers k such that 2^k contains 2^6=64 as its largest proper substring of the form 2^m.

26, 31, 46, 59, 66, 67, 72, 77, 83, 86, 89, 92, 96, 101, 106, 111, 116, 119, 123, 124, 125, 126, 129, 131, 136, 138, 141, 142, 144, 148, 152, 153, 155, 157, 163, 165, 166, 171, 176, 177, 178, 181, 182, 183, 186, 193, 194, 197, 198, 199, 202, 204, 205, 206

Offset

1,1

Comments

If there is a term beyond a(747) = 7954, it is larger than 250000. - Giovanni Resta, Oct 14 2019

Links

Giovanni Resta, Table of n, a(n) for n = 1..747

Example

2^26 = 671088{64};
2^31 = 2147483{64}8;
2^46 = 703687441776{64}.

Mathematica

sub2[n_] := Block[{s = ToString[2^n], k = n - 1}, While[k >= 0 && ! StringContainsQ[s, ToString[2^k]], k--]; k]; Select[Range[300], sub2[#] == 6 &] (* Giovanni Resta, Oct 14 2019 *)

Crossrefs

Cf. A033921.

Sequence in context: A282110 A373621 A275192 * A259041 A134252 A153224

Adjacent sequences: A046289 A046290 A046291 * A046293 A046294 A046295

Keyword

nonn,base

Author

Patrick De Geest, Jun 15 1998

Status

approved