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A046289
Numbers k such that 2^k contains 2^3=8 as its largest proper substring of the form 2^m (probably finite).
0
7, 11, 13, 19, 20, 23, 27, 28, 29, 30, 33, 34, 35, 36, 37, 38, 39, 42, 43, 48, 50, 51, 54, 55, 57, 58, 60, 61, 63, 68, 69, 74, 79, 80, 87, 88, 90, 91, 93, 94, 113, 115, 121, 128, 130, 139, 149, 150, 168, 169, 172, 173, 174, 187, 229, 337, 338, 376, 417
OFFSET
1,1
MATHEMATICA
sub2[n_] := Block[{s = ToString[2^n], k = n - 1}, While[k >= 0 && ! StringContainsQ[s, ToString[2^k]], k--]; k]; Select[Range[500], sub2[#] == 3 &] (* Giovanni Resta, Oct 14 2019 *)
CROSSREFS
Cf. A033921.
Sequence in context: A060772 A257125 A064149 * A092246 A084468 A292315
KEYWORD
nonn,base
AUTHOR
Patrick De Geest, Jun 15 1998
STATUS
approved