OFFSET
3,1
COMMENTS
This is an integer by a theorem of Waring and Wolstenholme.
LINKS
R. Mestrovic, Wolstenholme's theorem: Its Generalizations and Extensions in the last hundred and fifty years (1862-2011), arXiv:1111.3057, 2011
MAPLE
f1:=proc(n) local p;
p:=ithprime(n);
(1/p)*numer(add(1/i^2, i=1..p-1));
end proc;
[seq(f1(n), n=3..20)];
MATHEMATICA
a = {}; Do[AppendTo[a, (1/(Prime[x]))Numerator[Sum[1/x^2, {x, 1, Prime[x] - 1}]]], {x, 3, 50}]; a
Table[Sum[1/k^2, {k, p-1}]/p, {p, Prime[Range[3, 20]]}]//Numerator (* Harvey P. Dale, Nov 20 2019 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Artur Jasinski, Jan 03 2007
STATUS
approved