login
A344872
Semiprimes of the form 3m+2.
2
14, 26, 35, 38, 62, 65, 74, 77, 86, 95, 119, 122, 134, 143, 146, 155, 158, 161, 185, 194, 203, 206, 209, 215, 218, 221, 254, 278, 287, 299, 302, 305, 314, 323, 326, 329, 335, 341, 362, 365, 371, 377, 386, 395, 398, 407, 413, 422, 437, 446, 458, 473, 482, 485, 497
OFFSET
1,1
COMMENTS
There are no square terms, as squares are congruent to 0 or 1 modulo 3.
Products of a prime of the form 3m+1 and a prime of the form 3m+2 (the former necessarily being of the form 6m+1).
EXAMPLE
14 = 2 * 7 has 2 prime factors (counting repetitions) so is a semiprime, and 14 = 3*4 + 2, so has the form 3m+2. So 14 is in the sequence.
MATHEMATICA
Select[Range[2, 500, 3], PrimeOmega@#==2&] (* Giorgos Kalogeropoulos, Jun 02 2021 *)
PROG
(PARI) isok(m) = bigomega(m) == 2 && m % 3 == 2;
CROSSREFS
Intersection of A001358 and A016789.
Disjoint union of A108172 and A112772.
Complement within A001358 of A001748, A112771 and A112774.
Subsequence of A344703.
Sequence in context: A079702 A235688 A176274 * A240227 A191992 A082773
KEYWORD
nonn,easy
AUTHOR
Peter Munn, May 31 2021
STATUS
approved