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A052057
Numbers k such that the decimal expansion of 2^k contains no palindromic substring except single digits.
2
0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 20, 21, 22, 29, 37, 54
OFFSET
1,3
COMMENTS
Sequence is probably finite. Next term, if it exists, exceeds 1170.
Next term, if it exists, exceeds 50000. - Sean A. Irvine, Oct 18 2021
EXAMPLE
Record number is 2^54 = 18014398509481984.
MATHEMATICA
Select[Range[0, 10^3], NoneTrue[DeleteCases[Subsequences@ IntegerDigits[2^#], _?(Length[#] <= 1 &)], PalindromeQ] &] (* Michael De Vlieger, Oct 18 2021 *)
CROSSREFS
KEYWORD
nonn,base,more
AUTHOR
Patrick De Geest, Jan 15 2000
EXTENSIONS
Edited by Jon E. Schoenfield, Oct 17 2019
STATUS
approved