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A364242
a(n) is the smallest positive integer such that a(n) and a(n)+2 are both products of n distinct prime factors.
0
3, 33, 663, 18445, 887313, 84946015, 3086525013, 557027507463, 31110090768183, 3404401335645583, 609352762511672905
OFFSET
1,1
EXAMPLE
a(2) = 33 = 3 * 11, a(2) + 2 = 35 = 5 * 7.
a(3) = 663 = 3 * 13 * 17, a(3) + 2 = 665 = 5 * 7 * 19.
PROG
(PARI) isok(k, n) = (omega(k)==n) && (omega(k+2)==n) && issquarefree(k) && issquarefree(k+2)
a(n) = my(k=1); while (!isok(k, n), k++); k; \\ Michel Marcus, Jul 16 2023
CROSSREFS
Cf. A052215.
Subsequence of A005117.
Sequence in context: A377453 A377446 A336636 * A376390 A376393 A091462
KEYWORD
nonn,hard,more
AUTHOR
Tomek Czajka, Jul 15 2023
STATUS
approved