A290393 Numbers that are not the difference of two binary palindromes (A006995).

1844, 1892, 2512, 3700, 4702, 5476, 5534, 7364, 7784, 7876, 8068, 8080, 8440, 8596, 8632, 8764, 9100, 9308, 9334, 9404, 10000, 10108, 10120, 10348, 10456, 10480, 10744, 10844, 11024, 11504, 11588, 12604, 12722, 13714, 14576, 15812, 16150, 16622, 17300, 17820, 17950, 18316, 18622, 21100, 21400, 21860

Offset

1,1

Comments

Not currently known to be an infinite sequence.

Based on b-file of Giovanni Resta, the smallest value of a(n) such that a(n+1) - a(n) = 2 is 76156. - Altug Alkan, Aug 08 2017

Links

Giovanni Resta, Table of n, a(n) for n = 1..342 (terms <= 10^5)

Mathematica

g[w_] := FromDigits[Join @@ w, 2]; bp[1] = {1}; bp[n_] := Block[{b, r, h = Floor[n/2]}, Sort@ Flatten@ Table[b = IntegerDigits[k, 2, h]; r = Reverse@b; If[OddQ@n, g /@ {{b, {0}, r}, {b, {1}, r}}, g@{b, r}], {k, 2^h/2, 2^h - 1}]]; pp = Sort@Flatten[Table[bp[h], {h, 32}]]; T = Range[50000] * 0; i = 0; While[i < Length[pp] - 1, i++; j = i+1; While[j <= Length[pp] && (d = pp[[j]] - pp[[i]]) <= 10^5, T[[d/2]] = 1; j++]]; 2 Flatten[Position[T, 0]] (* Giovanni Resta, Aug 08 2017 *)

Crossrefs

Cf. A006995.

Sequence in context: A252214 A112017 A297894 * A251109 A236160 A209966

Adjacent sequences: A290390 A290391 A290392 * A290394 A290395 A290396

Keyword

nonn,base

Author

Jeffrey Shallit, Jul 29 2017

Status

approved