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A069627
Sum_{k=1..n} floor(n*(n-1)/(2*k)).
1
0, 0, 1, 5, 12, 22, 35, 53, 74, 101, 129, 162, 202, 244, 292, 344, 403, 463, 527, 601, 676, 762, 844, 937, 1035, 1138, 1245, 1355, 1476, 1597, 1726, 1862, 2002, 2149, 2300, 2454, 2621, 2784, 2957, 3136, 3323, 3515, 3707, 3914, 4119, 4338, 4551, 4782, 5012, 5250
OFFSET
0,4
COMMENTS
The old entry with this sequence number was a duplicate of A072137.
FORMULA
a(n) ~ n^2 * (gamma + log(n))/2, where gamma is the Euler-Mascheroni constant A001620. - Vaclav Kotesovec, Dec 23 2020
MAPLE
f:=n->add(floor( n*(n-1)/(2*k) ), k=1..n );
CROSSREFS
Sequence in context: A022795 A025734 A153818 * A034971 A025740 A225247
KEYWORD
nonn
AUTHOR
N. J. A. Sloane, Oct 28 2008
STATUS
approved