

A290136


Positive numbers that are not the sum of two nonprime squarefree numbers (A000469).


1



1, 3, 4, 5, 6, 8, 9, 10, 13, 14, 17, 18, 19, 26, 33, 38, 46, 62, 82
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OFFSET

1,2


COMMENTS

The sequence is conjectured to be complete.


LINKS

Table of n, a(n) for n=1..19.


MATHEMATICA

nmax = 82; f[x_] := Sum[Boole[SquareFreeQ[k] && PrimeNu[k] != 1] x^k, {k, 1, nmax}]^2; b = Exponent[#, x] & /@ List @@ Normal[Series[f[x], {x, 0, nmax}]]; c = Complement[Range[nmax], b][[1 ;; 19]]


CROSSREFS

Cf. A000469, A014092, A071068, A071331, A098235, A239508, A239509.
Sequence in context: A253897 A100966 A063977 * A332739 A306588 A219636
Adjacent sequences: A290133 A290134 A290135 * A290137 A290138 A290139


KEYWORD

nonn,more


AUTHOR

Ilya Gutkovskiy, Jul 20 2017


STATUS

approved



