OFFSET
1,1
COMMENTS
Primes prime(n) such that prime(n)*prime(n+3)-prime(n+1)*prime(n+2) is positive.
EXAMPLE
17 belongs to the sequence as 17 is prime, it is the 7th prime, 8th is 19, 9th is 23, 10th is 29, and the matrix [17,19;23,29] has a determinant of 56, which is positive.
PROG
(Octave) p=primes(1000); for n=1:100 m=[p(n), p(n+1); p(n+2), p(n+3)]; if det(m)>0 disp(p(n)) end end
(PARI) lista(nn) = {forprime(p=2, nn, q=nextprime(p+1); r=nextprime(q+1); if (p*nextprime(r+1) - q*r > 0, print1(p, ", ")); ); } \\ Michel Marcus, Mar 09 2015
CROSSREFS
KEYWORD
nonn
AUTHOR
Pierandrea Formusa, Mar 08 2015
STATUS
approved