A124792 - OEIS

A124792

Numbers n such that n and A001414(n) are 3-almost primes.

18, 42, 50, 78, 92, 110, 130, 138, 154, 164, 222, 230, 236, 266, 282, 284, 285, 338, 357, 366, 370, 374, 404, 425, 426, 429, 430, 438, 452, 555, 574, 582, 590, 596, 602, 605, 610, 637, 638, 654, 668, 682, 710, 754, 764, 782, 814, 826, 854, 874, 894, 908, 938

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OFFSET

1,1

COMMENTS

Cf. A014612 = 3-almost primes, A001414 = sopfr(n).

LINKS

Charles R Greathouse IV, Table of n, a(n) for n = 1..10000

EXAMPLE

8 is not here because 8=2*2*2=>2+2+2=6=2*3 (semiprime),

12 is not here because 12=2*2*3=>2+2+3=7 (prime),

18 is here because 18=2*3*3=>2+3+3=8=2*2*2 (3-almost prime),

20, 27, 28, 30, are not here,