OFFSET
1,2
LINKS
R. Mestrovic, Wolstenholme's theorem: Its Generalizations and Extensions in the last hundred and fifty years (1862-2011), arXiv:1111.3057 [math.NT], 2011.
MAPLE
f2:=proc(n) local p;
p:=ithprime(n);
denom(add(1/i^2, i=1..p-1));
end proc;
[seq(f2(n), n=1..20)];
MATHEMATICA
a[n_] := HarmonicNumber[Prime[n] - 1, 2] // Denominator;
Array[a, 15] (* Jean-François Alcover, Nov 25 2017 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
N. J. A. Sloane, Jan 21 2012
STATUS
approved