%I
%S 4,5,7,9,11,19,21,31,33,39,49,51,81,99,101,123,129,159,171,177,189,
%T 231,291,441,879,1011,2751
%N Numbers n such that more than half the positive members of the sequence k^2 + n*k  1 are primes.
%C Numbers n such that more than half the terms in row n of the triangular array A059036 are prime.
%C All positive members of the sequence are prime for n = 1, 2, 4, 5, 9 and 21.
%C There are no more terms below 200000.  _Pontus von BrÃ¶mssen_, Jul 06 2020
%e 7 is in the sequence because with g(k) = k^2+7*k1, the positive members of the sequence g(k) are 5=g(1), 9=g(2) and 11=g(3), and two out of the three (5 and 9) are prime.
%p filter:= n > nops(select(isprime, [seq(n*xx^21,x=1..n/2)])) > 1/2*floor(n/2):
%p select(filter, [$1..10000]);
%Y Cf. A059036.
%K nonn,more
%O 1,1
%A _Robert Israel_, Jul 03 2020
