OFFSET
1,2
COMMENTS
Terms corresponding to indices m = a(k) > 1000 are not certified primes but at least probable primes. Is there a simple explanation for the large gaps between a(k)=38 and a(k+1)=376; a(k)=864 and a(k+1)=2670, etc.?
EXAMPLE
PROG
(PARI) print_A137691(i=0/*start checking at i+1*/)={my(s=sum(j=1, i, 1/(prime(j)-1))); while(1, while(!ispseudoprime(1+denominator(s+=1/(prime(i++)-1))), ); print1(i", "))}
CROSSREFS
KEYWORD
hard,nonn
AUTHOR
M. F. Hasler, Feb 07 2008
EXTENSIONS
Edited by T. D. Noe, Oct 30 2008
STATUS
approved