

A290393


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


2



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
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OFFSET

1,1


COMMENTS

Not currently known to be an infinite sequence.
Based on bfile 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



