OFFSET
1,1
COMMENTS
Sequence is infinite: All integers of the forms either 2*prime or 3*prime plus 6 are here.
Suggestion: all odd terms are multiples of 3 except for four primes 13, 23, 29, 41.
LINKS
Zak Seidov, Table of n, a(n) for n = 1..10000
EXAMPLE
10 = 2*2 + 3*2, 12 = 2*3 + 3*2, 13 = 2*2 + 3*3.
MATHEMATICA
mx = 260; Sort[First /@ Select[Tally[ Flatten@Table[2 Prime[i] + 3 Prime[k], {k, PrimePi[(mx - 4)/3]}, {i, PrimePi[(mx - 3 Prime[k])/2]}]], #[[2]] < 2 &]]
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]++)); for(i=1, #v, if(v[i]==1, listput(u, i))); Vec(u) \\ Charles R Greathouse IV, Dec 05 2012
CROSSREFS
KEYWORD
nonn
AUTHOR
Zak Seidov, Dec 02 2012
STATUS
approved