A219955 Numbers that cannot be represented as 2*p + 3*q, where p and q are prime.

1, 2, 3, 4, 5, 6, 7, 8, 9, 11, 14, 17, 18, 22, 24, 26, 30, 33, 34, 36, 38, 42, 46, 48, 50, 51, 54, 56, 58, 60, 62, 66, 69, 70, 72, 74, 76, 78, 81, 82, 84, 86, 87, 90, 94, 96, 98, 102, 104, 105, 106, 108, 110, 111, 114, 116, 118, 120, 122, 123, 126, 130, 132

Offset

1,2

Comments

Numbers not in A079026.

Links

Zak Seidov, Table of n, a(n) for n = 1..1000

Formula

a(n) < 1.5n + O(n/log n). - Charles R Greathouse IV, Dec 04 2012

Mathematica

mx = 200; Complement[Range[mx], Flatten@Table[2 Prime[i] + 3 Prime[k], {k, PrimePi[(mx - 4)/3]}, {i, PrimePi[(mx - 3 Prime[k])/2]}]] (* Zak Seidov, Dec 04 2012 *)

Prog

(PARI) list(lim)=my(v=vectorsmall(lim\1), u=List()); forprime(p=2, lim\2, forprime(q=2, (lim-2*p)\3, v[2*p+3*q]=1)); for(i=1, #v, if(!v[i], listput(u, i))); Vec(u) \\ Charles R Greathouse IV, Dec 04 2012

Crossrefs

Cf. A079026.

Sequence in context: A085429 A202940 A082324 * A079064 A123176 A017902

Adjacent sequences: A219952 A219953 A219954 * A219956 A219957 A219958

Keyword

nonn

Author

Zak Seidov, Dec 02 2012

Status

approved