OFFSET
1,4
LINKS
G. C. Greubel, Table of n, a(n) for n = 1..68
EXAMPLE
{b(n)}:1,1,2,3/2,8/3,11/8,71/22,93/71,...So b(7) = sum{k|6} 1/b(k) = 1/b(1) + 1/ b(2) + 1/b(3) + 1/b(6) = 1 + 1 + 1/2 + 8/11 = 71/22.
MATHEMATICA
f[l_List] := Block[{n = Length[l], d = Divisors[n]}, Append[l, Sum[1/l[[d[[i]]]], {i, Length[d]}]]]; Denominator[Nest[f, {1}, 22]] (* Ray Chandler, Feb 09 2007 *)
CROSSREFS
KEYWORD
frac,nonn
AUTHOR
Leroy Quet, Feb 08 2007
EXTENSIONS
Extended by Ray Chandler, Feb 09 2007
STATUS
approved