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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 (list; graph; refs; listen; history; text; internal format)
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

LINKS

Table of n, a(n) for n=1..22.

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

Cf. A000079, A050723, A052058, A052059.

Sequence in context: A341750 A246096 A098314 * A252493 A005496 A052060

Adjacent sequences:  A052054 A052055 A052056 * A052058 A052059 A052060

KEYWORD

nonn,base,more

AUTHOR

Patrick De Geest, Jan 15 2000

EXTENSIONS

Edited by Jon E. Schoenfield, Oct 17 2019

STATUS

approved

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Last modified October 3 10:36 EDT 2022. Contains 357231 sequences. (Running on oeis4.)