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A219955
Numbers that cannot be represented as 2*p + 3*q, where p and q are prime.
7
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.
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
KEYWORD
nonn
AUTHOR
Zak Seidov, Dec 02 2012
STATUS
approved