login
A046292
Numbers k such that 2^k contains 2^6=64 as its largest proper substring of the form 2^m.
1
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
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
KEYWORD
nonn,base
AUTHOR
Patrick De Geest, Jun 15 1998
STATUS
approved