A331891 Negabinary palindromes: nonnegative numbers whose negabinary expansion (A039724) is palindromic.

0, 1, 3, 5, 7, 11, 17, 21, 23, 31, 43, 51, 57, 65, 77, 85, 87, 103, 127, 143, 155, 171, 195, 211, 217, 233, 257, 273, 285, 301, 325, 341, 343, 375, 423, 455, 479, 511, 559, 591, 603, 635, 683, 715, 739, 771, 819, 851, 857, 889, 937, 969, 993, 1025, 1073, 1105, 1117

Offset

1,3

Comments

Numbers of the form 2^(2*m-1) - 1 (A083420) and 2^(2*m) + 1 (A052539) are terms.

Links

Amiram Eldar, Table of n, a(n) for n = 1..10000

Example

5 is a term since its negabinary representation is 101 which is palindromic.

Mathematica

negabin[n_] := negabin[n] = If[n==0, 0, negabin[Quotient[n-1, -2]]*10 + Mod[n, 2]]; Select[Range[0, 1200], PalindromeQ @ negabin[#] &]

Crossrefs

Cf. A002113, A006995, A014190, A039724, A094202, A331191.

Sequence in context: A211409 A152998 A222176 * A331896 A108539 A170886

Adjacent sequences: A331888 A331889 A331890 * A331892 A331893 A331894

Keyword

nonn,base

Author

Amiram Eldar, Jan 30 2020

Status

approved