cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A273245 Non-palindromic binary numbers whose reversal is a palindrome.

Original entry on oeis.org

10, 100, 110, 1000, 1010, 1100, 1110, 10000, 10010, 10100, 11000, 11100, 11110, 100000, 100010, 100100, 101000, 101010, 110000, 110110, 111000, 111100, 111110, 1000000, 1000010, 1000100, 1001000, 1010000, 1010100, 1011010, 1100000, 1100110, 1101100, 1110000, 1111000, 1111100
Offset: 1

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Author

Giovanni Teofilatto, May 18 2016

Keywords

Crossrefs

Cf. A006995, A273329, A272670 (this sequence written in base 10), A057890 (and divided by 2).

Programs

  • Maple
    # see A272670 for the other subroutines
    for n from 1 to 400 do
        if isA272670(n) then
            printf("%d,",A007088(n)) ;
        end if;
    end do: # R. J. Mathar, May 20 2016
  • Python
    A273245_list = [int(m) for m in (bin(n)[2:] for n in range(1,10**4)) if m != m[::-1] and m.rstrip('0') == m[::-1].lstrip('0')] # Chai Wah Wu, May 21 2016

Formula

Consists of binary palindromes (A006995) times nontrivial powers of 2, that is, 2^i, i>0. - N. J. A. Sloane, May 19 2016
a(n) = A007088(A272670(n)). - R. J. Mathar, May 20 2016