A046288 Numbers k such that 2^k contains 2^2=4 as its largest proper substring of the form 2^m (probably finite).

6, 10, 12, 18, 22, 32, 49, 52, 53, 56, 78

Offset: 1

Author

Patrick De Geest, Jun 15 1998

Keywords

• nonn
• base
• more

Crossrefs

Cf. A033921.

Programs

Mathematica

sub2[n_] := Block[{s = ToString[2^n], k = n - 1}, While[k >= 0 && ! StringContainsQ[s, ToString[2^k]], k--]; k]; Select[Range[1000], sub2[#] == 2 &] (* Giovanni Resta, Oct 14 2019 *)