login
A120264
Numerator of Sum_{k=1..n} (-1)^(k+1)/k^k.
0
1, 3, 85, 5413, 16922537, 456895999, 376274084904457, 24659496552164597077, 13105067550356276873597957, 40953336089635928267832533257, 11684464736880059106484670339210887010027
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
Cf. A083648.
Sequence in context: A056262 A042587 A156879 * A292830 A185142 A279020
KEYWORD
frac,nonn
AUTHOR
Alexander Adamchuk, Jun 30 2006
STATUS
approved