A110188 3-almost primes p * q * r not relatively prime to p+q+r.

8, 18, 27, 30, 42, 50, 66, 70, 78, 98, 102, 105, 110, 114, 125, 130, 138, 154, 170, 174, 182, 186, 190, 195, 222, 230, 231, 238, 242, 246, 255, 258, 266, 282, 285, 286, 290, 310, 318, 322, 338, 343, 354, 357, 366, 370, 374, 402, 406, 410, 418, 426, 429, 430

Offset: 1

Author

Jonathan Vos Post, Jul 15 2005

Keywords

• easy
• nonn

Comments

A110187 is the converse, 3-almost primes p * q * r which are relatively prime to p+q+r.

Examples

			a(1) = 8 because 8 = 2^3, which has a prime factor 2 in common with prime 2 + 2 + 2 = 6.
30 is in the sequence, since 30 = 2 * 3 * 5, which is in fact divisible by 2 + 3 + 5 = 10.
		

Links

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

Crossrefs

Cf. A014612, A110187, A110227, A110228, A110229, A110230, A110231, A110232, A110289, A110290, A110296, A110297.

Programs

PARI

list(lim)=my(v=List()); forprime(p=2, lim\4, forprime(q=2, min(p, lim\2\p), my(pq=p*q, t); forprime(r=2, min(lim\pq, q), t=r*pq; if(gcd(t, p+q+r)>1, listput(v, t))))); Set(v) \\ Charles R Greathouse IV, Jan 31 2017

Extensions

Extended by Ray Chandler, Jul 20 2005