OFFSET
1,2
COMMENTS
Partial sums of A007069.
LINKS
G. C. Greubel, Table of n, a(n) for n = 1..5000
FORMULA
a(n) = n*(n-1+1/sqrt(2)) + O(1).
MATHEMATICA
Table[Sum[Floor[Sqrt[2]Floor[Sqrt[2]x]], {x, n}], {n, 60}] (* Harvey P. Dale, Jul 20 2018 *)
PROG
(PARI) a(n) = sum(i=1, n, floor(sqrt(2)*floor(sqrt(2)*i))); \\ Michel Marcus, Dec 05 2013
(Magma) [(&+[Floor(Sqrt(2)*Floor(Sqrt(2)*j)): j in [1..n]]): n in [1..60]]; // G. C. Greubel, Oct 01 2018
CROSSREFS
KEYWORD
nonn
AUTHOR
Benoit Cloitre, Jun 13 2003
STATUS
approved