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Primes not of the form p*q + p - q with prime p and q.
1

%I #6 Mar 20 2015 03:15:23

%S 2,3,11,23,47,53,59,71,79,83,101,107,131,163,167,173,179,191,223,227,

%T 239,251,263,269,293,311,331,347,359,367,383,419,431,439,443,467,479,

%U 491,503,509,547,563,587,599,607,641,647,653,659,683,691,719,727,733

%N Primes not of the form p*q + p - q with prime p and q.

%t x = Take[ Select[ Union[ Flatten[ Table[ Prime[p]*Prime[q] + Prime[p] - Prime[q], {p, 116}, {q, 116}]]], PrimeQ[ # ] &], 200]; y = Table[ Prime[i], {i, PrimePi[ p[[ -1]] ]}]; Take[ Complement[y, x], 54] (* _Robert G. Wilson v_ *)

%Y Primes not in A091301.

%K nonn

%O 1,1

%A _Zak Seidov_, Feb 21 2004