|
|
A064016
|
|
a(n) = Sum_{k <= 10^n} cototient(k), where cototient is A051953.
|
|
0
|
|
|
0, 23, 2006, 196308, 19607514, 1960399246, 196036947608, 19603648572758, 1960364533634092, 196036449326991586, 19603644912113783634, 1960364490766613788860, 196036449073440195974090, 19603644907302101080472556, 1960364490729905106089642146, 196036449072986990521291164848
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
0,2
|
|
COMMENTS
|
It appears that lim_{n->infinity} (1/n^2) * Sum_{j=1..n} a(j) = 0.1960364... = (1/2 - 3/Pi^2).
|
|
LINKS
|
|
|
FORMULA
|
|
|
MATHEMATICA
|
s = 0; k = 1; Do[ While[ k <= 10^n, s = s + k - EulerPhi[ k ]; k++ ]; Print[ s ], {n, 0, 8} ]
|
|
CROSSREFS
|
|
|
KEYWORD
|
nonn
|
|
AUTHOR
|
|
|
EXTENSIONS
|
|
|
STATUS
|
approved
|
|
|
|