0,1

The sum of the reciprocals of the terms appears to converge.

(PARI) triprimes(n) = { sr = 0; for(j=1, n, x = j*(j+1)/2+2; z = prime(x); sr+=1.0/z; print1(z" "); ); print(); print(sr); }

Apart from initial terms, primes in third diagonal of triangle in A078721.

Sequence in context: A105904 A038901 A155006 this_sequence A155757 A027674 A124307

Adjacent sequences: A078721 A078722 A078723 this_sequence A078725 A078726 A078727

easy,nonn

Cino Hilliard (hillcino368(AT)gmail.com), Dec 20 2002