OFFSET
1,2
COMMENTS
The numbers of digits of the terms are 1, 2, 5, 12, 30, 84, 215, 537, 1237, 2930, 6775, 15484, 35185, ... .
LINKS
FORMULA
EXAMPLE
Fractions begins: 1, 13/10, 51227/36540, 926908275845/636617813832, 548123689541583443758024333411/369693143251781030056182487680, ...
MATHEMATICA
d[k_, n_] := Product[1 - 1/Prime[i]^k, {i, 1, n}]; f[n_] := Sum[k * (d[k+1, n] - d[k, n]), {k, 1, Infinity}]; Numerator[Array[f, 6]]
CROSSREFS
KEYWORD
nonn,frac
AUTHOR
Amiram Eldar, Aug 19 2024
STATUS
approved