|
|
A083656
|
|
a(n) = Sum_{i=1..n} floor(r*floor(r*i)), where r=sqrt(2).
|
|
1
|
|
|
1, 3, 8, 15, 24, 35, 47, 62, 78, 97, 118, 140, 165, 191, 220, 251, 284, 319, 355, 394, 435, 478, 523, 569, 618, 668, 721, 776, 833, 892, 952, 1015, 1080, 1147, 1216, 1286, 1359, 1433, 1510, 1589, 1669, 1752, 1836, 1923, 2012, 2103, 2196, 2290, 2387, 2485, 2586
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
1,2
|
|
COMMENTS
|
|
|
LINKS
|
|
|
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
|
|
|
STATUS
|
approved
|
|
|
|