A290424 Even numbers that are not the sum or difference of two binary palindromes (A006995).
9404, 10120, 13714, 14576, 15812, 18622, 35102, 35438, 38696, 39164, 39656, 40072, 40712, 42776, 43096, 43256, 43780, 44560, 45284, 45796, 46346, 46532, 46624, 46858, 46880, 46984, 47936, 49622, 50810, 55048, 56600, 58564, 60932, 61190, 62792, 62986, 67816, 69244
Offset: 1
Programs
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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[35000]*0; i = 0; While[i < Length[pp] - 1, i++; j = i + 1; While[j <= Length[pp] && (d = pp[[j]] - pp[[i]]) <= 70000, T[[d/2]] = 1; j++]]; pp = Select[pp, # <= 70000 &]; Select[2 Flatten[ Position[T, 0]], {} == Quiet@ IntegerPartitions[#, {2}, pp, 1] &] (* Giovanni Resta, Aug 08 2017 *)
Extensions
a(7)-a(38) from Giovanni Resta, Aug 08 2017
Comments