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

1,1

Comments

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

Links

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

Example

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.

Prog

(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

Crossrefs

Cf. A000069, A001969, A027699, A230213.

Sequence in context: A291133 A027456 A158372 * A233482 A027527 A069421

Adjacent sequences: A230350 A230351 A230352 * A230354 A230355 A230356

Keyword

nonn,base

Author

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

Status

approved