

A057891


In base 2, neither a palindrome nor becomes a palindrome if trailing 0's are omitted.


8



11, 13, 19, 22, 23, 25, 26, 29, 35, 37, 38, 39, 41, 43, 44, 46, 47, 49, 50, 52, 53, 55, 57, 58, 59, 61, 67, 69, 70, 71, 74, 75, 76, 77, 78, 79, 81, 82, 83, 86, 87, 88, 89, 91, 92, 94, 95, 97, 98, 100, 101, 103, 104, 105, 106, 109, 110, 111, 113, 114, 115, 116, 117, 118
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OFFSET

1,1


COMMENTS

These could be called "asymmetric bit strings".
If these numbers are converted to their binary polynomial, one of the roots of that polynomial will have absolute values other than 1 or 0. For example 11 = 2^3 + 2^1 + 2^0, the absolute values of the roots of x^3 + x + 1 are 0.682328... and 1.21061... which are not 1 or 0, so 11 is in the sequence. The first number with this property which is not a term is A057890(53) = 107.  Benedict W. J. Irwin, Sep 07 2017 and Andrey Zabolotskiy, Oct 13 2017


LINKS



FORMULA



EXAMPLE

11 is included because 1011 is asymmetrical, but 12 is not because 001100 is a palindrome.


PROG

(Haskell)
a057891 n = a057891_list !! (n1)
a057891_list = filter ((== 0) . a178225 . a000265) [1..]


CROSSREFS



KEYWORD

easy,nonn,base


AUTHOR



EXTENSIONS



STATUS

approved



