OFFSET
1,2
COMMENTS
No more terms up to and including m = 2000. - Harvey P. Dale, Dec 16 2018
EXAMPLE
a(2)=2 2/3 + 3/5 = 19/15 and 19 is prime and prime(2+1)=5.
a(3)=4 because 2/3+3/5+5/7+7/11 = 3023/1155 and 3023 is prime and prime(4+1)=11.
MATHEMATICA
Position[Numerator[Accumulate[#[[1]]/#[[2]]&/@Partition[Prime[ Range[ 800]], 2, 1]]], _?(PrimeQ[#]&)]//Flatten (* Harvey P. Dale, Dec 16 2018 *)
PROG
(PARI) pp(n)= s=0; for (i=1, n, s=s+prime(i)/prime(i+1)); return(s); for (i=1, 800, if(isprime(numerator(pp(i))), print(i)))
CROSSREFS
KEYWORD
hard,nonn
AUTHOR
Mohammed Bouayoun (bouyao(AT)wanadoo.fr), Feb 16 2004
EXTENSIONS
a(11)-a(12) from Michael S. Branicky, Aug 27 2024
STATUS
approved