A230353 Products of 3 evil primes (A027699) p,q,r, such that numbers p*q, p*r, q*r, and p*q*r are odious (A000069).

575, 1775, 2075, 2225, 2825, 3475, 6575, 8381, 8675, 8825, 8975, 8993, 10235, 11225, 11675, 11975, 12035, 12167, 12905, 13075, 14275, 14825, 18745, 19925, 21575, 22881, 23943, 24389, 25325, 25775, 26765, 27575, 30189, 30925, 30981, 31433, 32223, 32675, 32975

Offset: 1

Author

Vladimir Shevelev and Peter J. C. Moses, Oct 16 2013

Keywords

• nonn
• base

Comments

These numbers are products of 3 evil numbers (A001969) but not represented as products of two evil numbers (A230213).

Examples

			For triple of evil primes {3,29,263} numbers 3*29 = 87, 3*263 = 789, 29*263 = 7627 and 3*29*263 = 22881. Thus 22881 is in the sequence.
		

Links

• Charles R Greathouse IV and Peter J. C. Moses, Table of n, a(n) for n = 1..10000 (first 500 from Moses)

Crossrefs

Cf. A000069, A001969, A027699, A230213.

Programs

PARI

od(n)=hammingweight(n)%2
list(lim)=my(v=List(),pq); forprime(p=23,lim\25, if(od(p), next); forprime(q=5,min(lim\(3*p),p), if(od(q) || !od(pq=p*q), next); forprime(r=3,min(lim\pq,q), if(!od(r) && od(q*r) && od(p*r) && od(pq*r), listput(v, pq*r))))); vecsort(Vec(v)) \\ Charles R Greathouse IV, Nov 01 2013