OFFSET
1,2
COMMENTS
How is the distribution of a(n), a(n+1) in this sequence where a(n+1) = a(n) + 1?
EXAMPLE
1 is a term because prime(1) = 2 = (-2)^2 + (-2) + (-2)*1 + 1 + 1^2.
3 is a term because prime(3) = 5 = 1^2 + 1 + 1*1 + 1 + 1^2.
7 is a term because prime(7) = 17 = (-5)^2 + (-5) + (-5)*3 + 3 + 3^2.
12 is a term because prime(12) = 37 = (-7)^2 + (-7) + (-7)*5 + 5 + 5^2.
13 is a term because prime(13) = 41 = 7^2 + 7 + 7*(-3) + (-3) + (-3)^2.
PROG
(PARI) isA003136(n) = #bnfisintnorm(bnfinit(z^2+z+1), n);
for(n=1, 250, if(isA003136(3*prime(n)+1), print1(n, ", ")));
CROSSREFS
KEYWORD
nonn
AUTHOR
Altug Alkan, Mar 11 2016
STATUS
approved