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A278643
Numbers that are not the sum of 3 or fewer terms of A277238.
0
27, 37, 47, 73, 83, 87, 125, 139, 141, 167, 175, 197, 237, 267, 273, 277, 281, 305, 307, 327, 335, 337, 345, 351, 379, 387, 397, 405, 421, 433, 463, 471, 477, 487, 505, 531, 537, 547, 567, 577, 589, 613, 619, 629, 631, 635, 659, 661, 665, 687, 691, 697, 703, 715, 727, 731, 743, 753, 789, 805, 821, 857, 877, 883, 919, 941
OFFSET
1,1
COMMENTS
Not known to be infinite. Also, it is not known if every integer is the sum of 4 or fewer terms of A277238, although this is true up to 2^20.
MATHEMATICA
Take[#, 66] &@ Complement[Range@ Max@ #, #] &@ Union@ Map[Total, Rest@ Tuples[{0}~Join~#, 3]] &@ Prepend[Select[Range[10^3], If[OddQ@ Length@ # && Take[#, {Ceiling[Length[#]/2]}] == {0}, False, Union[Take[#, Floor[Length[#]/2]] + Reverse@ Take[#, -Floor[Length[#]/2]]] == {1}] &@ IntegerDigits[#, 2] &], 1] (* Michael De Vlieger, Nov 25 2016 *)
CROSSREFS
Cf. A277238.
Sequence in context: A025145 A266963 A180961 * A069105 A159259 A365960
KEYWORD
nonn
AUTHOR
Jeffrey Shallit, Nov 24 2016
STATUS
approved