OFFSET
1,2
LINKS
Robert Israel, Table of n, a(n) for n = 1..10000
FORMULA
a(n) = Numerator(Sum_{i=1..n} 1/(prime(i+1)-prime(i)).
a(n) = Numerator(Sum_{i=1..n} 1/A001223(i)).
MAPLE
Primes:= select(isprime, [2, seq(i, i=3..10^4, 2)]):
map(numer, ListTools:-PartialSums(map(`^`, Primes[2..-1]-Primes[1..-2], -1))); # Robert Israel, Jul 26 2016
MATHEMATICA
nmax=51; Table[Sum[1/(Prime[j + 1] - Prime[j]), {j, 1, n}], {n, 1, nmax}]//Numerator;
Accumulate[1/Differences[Prime[Range[60]]]]//Numerator (* Harvey P. Dale, Dec 25 2017 *)
PROG
(PARI) a(n) = numerator(sum(i=1, n, 1/(prime(i+1)-prime(i)))) \\ Felix Fröhlich, Jul 07 2016
CROSSREFS
KEYWORD
AUTHOR
Andres Cicuttin, Jul 07 2016
STATUS
approved