OFFSET
1,2
COMMENTS
Denominator of Sum_{k=1..n} (1/k^k)*(-1)^(k+1) is A061464(n).
Sum_{k>=1} (-1)^(k+1)/k^k = Integral_{x=0..1} x^x dx = 0.7834305107121344... A083648(n) gives its decimal expansion {7, 8, 3, 4, 3, 0, 5, 1, 0, 7, 1, 2, 1, 3, 4, 4, 0, 7, 0, 5, 9, ...}. - Alexander Adamchuk, Aug 21 2006
LINKS
Eric Weisstein's World of Mathematics, Sophomore's Dream.
FORMULA
a(n) = numerator(Sum_{k=1..n} (1/k^k)*(-1)^(k+1)).
MATHEMATICA
Numerator[Table[Sum[1/k^k*(-1)^(k+1), {k, 1, n}], {n, 1, 20}]]
CROSSREFS
KEYWORD
frac,nonn
AUTHOR
Alexander Adamchuk, Jun 30 2006
STATUS
approved