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A063645
Primes with two representations: p*q*r - 2 = u*v*w + 2 where p, q, r, u, v and w are primes (not necessarily distinct).
2
173, 277, 607, 929, 1129, 1181, 1237, 1493, 1549, 1597, 1613, 2011, 2063, 2137, 2423, 2677, 2753, 2767, 2797, 2819, 2851, 2917, 3449, 3533, 3607, 3617, 3727, 4013, 4073, 4177, 4201, 4253, 4493, 4523, 4583, 4691, 4919, 4951, 5119, 5237, 5273, 5393, 5407, 5557
OFFSET
1,1
LINKS
Alois P. Heinz, Table of n, a(n) for n = 1..10000 (first 1000 terms from Harry J. Smith)
EXAMPLE
A063645(50) = 5821: 5821 = A063641(204) = 5823 - 2 = 3*3*647 - 2, 5821 = A063642(225) = 5819 + 2 = 11*23*23 + 2.
MAPLE
q:= p-> isprime(p) and map(numtheory[bigomega], {p-2, p+2})={3}:
select(q, [$2..6000])[]; # Alois P. Heinz, Apr 01 2024
PROG
(PARI) { n=0; for (m=2, 10^9, p=prime(m); if (bigomega(p + 2) == 3 && bigomega(p - 2) == 3, write("b063645.txt", n++, " ", p); if (n==1000, break)) ) } \\ Harry J. Smith, Aug 27 2009
CROSSREFS
KEYWORD
nonn
AUTHOR
Reinhard Zumkeller, Jul 21 2001
STATUS
approved