|
|
A128647
|
|
a(n) = numerator(Sum_{k=1..n} (-1)^(k+1)/(prime(k)-1)).
|
|
3
|
|
|
1, 1, 3, 7, 41, 3, 53, 437, 5167, 34189, 36037, 3833, 3987, 11521, 274223, 3458639, 103063291, 100392623, 34273501, 33510453, 308270747, 302107667, 12626774467, 12402802537, 25216220279, 124110148411, 2142721739387, 111888942151111
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
1,3
|
|
COMMENTS
|
|
|
LINKS
|
|
|
FORMULA
|
a(n) = numerator(Sum_{k=1..n} (-1)^(k+1)/(prime(k)-1)).
|
|
MATHEMATICA
|
Table[Numerator[Sum[(-1)^(k+1)*1/(Prime[k]-1), {k, 1, n}]], {n, 1, 36}]
|
|
CROSSREFS
|
Cf. A128648 (denominator(Sum_{k=1..n} (-1)^(k+1)/(prime(k)-1))).
Cf. A120271 (numerator(Sum_{k=1..n} 1/(prime(k)-1))).
|
|
KEYWORD
|
frac,nonn
|
|
AUTHOR
|
|
|
STATUS
|
approved
|
|
|
|