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A110296 8-almost primes p*q*r*s*t*u*v*w relatively prime to p+q+r+s+t+u+v+w. +0
12
384, 640, 864, 1408, 1664, 2016, 2176, 2400, 2432, 2944, 3240, 3712, 3744, 3968, 4374, 4536, 4736, 5248, 5280, 5472, 5504, 5600, 6016, 6240, 6784, 7128, 7392, 7552, 7808, 7840, 8424, 8576, 8800, 8928, 9088, 9120, 9344, 10112, 10400, 10584, 10624 (list; graph; listen)
OFFSET

1,1

COMMENT

The primes p, q, r, s, t, u, v, w are not necessarily distinct. The 8-almost primes are A046310. The converse, A110297, is 8-almost primes p*q*r*s*t*u*v*w which are not relatively prime to p+q+r+s+t+u+v+w.

EXAMPLE

864 is an element of this sequence because 864 = 2^5 * 3^3, so the sum of prime factors is 2 + 2 + 2 + 2 + 2 + 3 + 3 + 3 = 19 which is prime, hence relatively prime to 864. That is the same sum of prime factors as 640 = 2^7 * 5, hence 640 is also a member of this sequence. The sum of prime factors need not be prime for this membership, for example, 2432 = 2^7 * 19 has sum of prime factors 2 + 2 + 2 + 2 + 2 + 2 + 2 + 19 = 33 = 3 * 11, which is composite, yet relatively prime to 2432.

CROSSREFS

Cf. A046310, A110187, A110188, A110227, A110228, A110229, A110230, A110231, A110232, A110289, A110290, A110297.

Sequence in context: A046014 A046491 A046492 this_sequence A134175 A134241 A061403

Adjacent sequences: A110293 A110294 A110295 this_sequence A110297 A110298 A110299

KEYWORD

easy,nonn

AUTHOR

Jonathan Vos Post (jvospost3(AT)gmail.com), Jul 18 2005

EXTENSIONS

Corrected and extended by Ray Chandler (rayjchandler(AT)sbcglobal.net), Jul 20 2005

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Last modified November 25 20:09 EST 2009. Contains 167514 sequences.


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