A110230 5-almost primes p * q * r * s * t not relatively prime to p + q + r + s + t.

32, 72, 120, 162, 168, 180, 200, 243, 264, 270, 280, 312, 378, 392, 396, 408, 440, 450, 456, 520, 552, 588, 594, 612, 616, 630, 680, 696, 700, 702, 728, 744, 750, 760, 780, 828, 882, 888, 918, 920, 945, 952, 968, 984, 990, 1026, 1032, 1044, 1050, 1064, 1092

Offset

1,1

Comments

p, q, r, s, t are not necessarily distinct. The converse to this is A110229: 5-almost primes p * q * r * s * t which are relatively prime to p+q+r+s+t. A014614 is the 5-almost primes.

Links

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

Example

180 is in this sequence because 180 = 2^2 * 3^2 * 5, the sum of the prime factors being 2 + 2 + 3 + 3 + 5 = 15 = 3 * 5 which has two prime factors in common with 180.

Prog

(PARI) list(lim)=my(v=List()); forprime(p=2, lim\16, forprime(q=2, min(p, lim\8\p), my(pq=p*q); forprime(r=2, min(lim\pq\4, q), my(pqr=pq*r); forprime(s=2, min(lim\pqr\2, r), my(pqrs=pqr*s, n); forprime(t=2, min(lim\pqrs, s), n=pqrs*t; if(gcd(n, p+q+r+s+t)>1, listput(v, n))))))); Set(v) \\ Charles R Greathouse IV, Jan 31 2017

Crossrefs

Cf. A014614, A110187, A110188, A110227, A110228, A110229, A110231, A110232, A110289, A110290, A110296, A110297.

Sequence in context: A216427 A104026 A216417 * A250756 A303583 A224220

Adjacent sequences: A110227 A110228 A110229 * A110231 A110232 A110233

Keyword

easy,nonn

Author

Jonathan Vos Post, Jul 17 2005

Extensions

Extended by Ray Chandler, Jul 20 2005

Status

approved