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A329857
Positive integers which can be represented as p*q - p - q where p and q are distinct odd primes.
0
7, 11, 19, 23, 31, 35, 39, 43, 47, 55, 59, 63, 71, 79, 83, 87, 91, 95, 103, 107, 111, 115, 119, 131, 139, 143, 155, 159, 163, 167, 175, 179, 183, 191, 199, 203, 207, 211, 215, 219, 223, 231, 239, 251, 259, 263, 271, 275, 279, 287, 295, 299, 311, 323, 327, 331, 335, 343, 347, 351, 355, 359
OFFSET
1,1
MATHEMATICA
Select[Range[360], {} != Solve[p*q-p-q == # && p >q> 2, {p, q}, Primes] &] (* Giovanni Resta, Jan 16 2020 *)
PROG
(PARI) lim=1000; x=[]; forprime(p=3, lim/3, forprime(q=p+2, lim/3, if(setsearch(x, p*q-q-p), , x=setunion(x, [p*q-q-p])))); for(i=1, length(x), if(x[i]<(lim), print1(x[i], ", ")))
CROSSREFS
Cf. A037165 (a subsequence), A046388, A091305, A096345, A137367 (subsequence with twin primes), A218862.
Sequence in context: A195759 A130570 A106081 * A168489 A329979 A129899
KEYWORD
nonn,easy
AUTHOR
Craig J. Beisel, Nov 22 2019
STATUS
approved