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

1,1

Links

Table of n, a(n) for n=1..11.

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 *)

Crossrefs

Cf. A033921.

Sequence in context: A315129 A315130 A315131 * A076763 A064712 A348629

Adjacent sequences: A046285 A046286 A046287 * A046289 A046290 A046291

Keyword

nonn,base,more

Author

Patrick De Geest, Jun 15 1998

Status

approved