A329857 Positive integers which can be represented as p*q - p - q where p and q are distinct odd primes.

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

Links

Table of n, a(n) for n=1..62.

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

Adjacent sequences: A329854 A329855 A329856 * A329858 A329859 A329860

Keyword

nonn,easy

Author

Craig J. Beisel, Nov 22 2019

Status

approved