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

Author

Jeffrey Shallit, Jul 29 2017

Keywords

• nonn
• base

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)

Crossrefs

Cf. A006995.

Programs

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 *)