OFFSET
1,2
LINKS
Eric Weisstein's World of Mathematics, Prime Sums.
EXAMPLE
MATHEMATICA
Denominator @ Accumulate @ Table[1/(Prime[k] - 1)^2, {k, 1, 21}] (* Amiram Eldar, May 12 2020 *)
PROG
(PARI) a(n) = denominator(sum(k=1, n, 1/(prime(k) - 1)^2)); \\ Michel Marcus, May 12 2020
CROSSREFS
KEYWORD
nonn,frac
AUTHOR
Petros Hadjicostas, May 11 2020
STATUS
approved