OFFSET
1,3
LINKS
Vaclav Kotesovec, Table of n, a(n) for n = 1..49
EXAMPLE
a(4) = 42, the denominator of 1/1 + 1/7 + 1/6 + 1 = 97/42.
The first few fractions are: 1, 2, 7/3, 97/42, 331/150, 77089/36270, 562609/270900.
MAPLE
with(combinat): a:=n->denom(sum(1/stirling2(n, k), k=1..n)): seq(a(n), n=1..15); # Emeric Deutsch, Sep 02 2005
MATHEMATICA
f[n_] := Sum[1/StirlingS2[n, k], {k, n}]; Table[Denominator[f[n]], {n, 15}] (* Ray Chandler, Sep 02 2005 *)
CROSSREFS
KEYWORD
nonn,frac
AUTHOR
Leroy Quet, Sep 01 2005
EXTENSIONS
Extended by Emeric Deutsch and Ray Chandler, Sep 02 2005
STATUS
approved