A290136 Positive numbers that are not the sum of two nonprime squarefree numbers (A000469).

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

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: A100966 A358973 A063977 * A359168 A332739 A306588

Adjacent sequences: A290133 A290134 A290135 * A290137 A290138 A290139

Keyword

nonn,more

Author

Ilya Gutkovskiy, Jul 20 2017

Status

approved