A280389 Odd semiprimes that can be represented as 2p+3q, where p and q are primes.
15, 21, 25, 35, 39, 49, 55, 57, 65, 77, 85, 91, 93, 95, 115, 119, 121, 129, 133, 143, 145, 155, 161, 169, 183, 185, 187, 203, 205, 209, 215, 217, 219, 221, 235, 247, 253, 259, 265, 287, 289, 295, 299, 301, 305, 309, 319, 323, 327, 329, 335, 341, 355, 361, 365, 371, 377, 391, 395, 403
Offset: 1
Keywords
Links
- Robert Israel, Table of n, a(n) for n = 1..10000
Crossrefs
Programs
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Maple
N:= 10^3: # to get all terms <= N Primes:= select(isprime, [2, seq(i, i=3..N/2, 2)]): Cands:= select(t -> t::odd and t <= N, {seq(seq(2*p+3*q, p=Primes), q=Primes)}): sort(convert(select(numtheory:-bigomega=2, Cands), list)); # Robert Israel, Jan 09 2017