|
|
A033551
|
|
Closest integer to (Pi/4)*n^2.
|
|
1
|
|
|
1, 3, 7, 13, 20, 28, 38, 50, 64, 79, 95, 113, 133, 154, 177, 201, 227, 254, 284, 314, 346, 380, 415, 452, 491, 531, 573, 616, 661, 707, 755, 804, 855, 908, 962, 1018, 1075, 1134, 1195, 1257, 1320, 1385, 1452, 1521
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
1,2
|
|
LINKS
|
|
|
FORMULA
|
a(n) = round( (Pi/4) * n^2 ).
|
|
EXAMPLE
|
a(3)=7, since 3^2*Pi/4 = 7.06858347.
|
|
MAPLE
|
seq(round((1/4)*Pi*n^2), n = 1..50); # G. C. Greubel, Oct 12 2019
|
|
MATHEMATICA
|
|
|
PROG
|
(Magma) R:= RealField(20); [Round(Pi(R)*n^2/4): n in [1..50]]; // G. C. Greubel, Oct 12 2019
(Sage) [round(pi*n^2/4) for n in (1..50)] # G. C. Greubel, Oct 12 2019
(GAP) List([1..50], n-> Int(Round(Atan(1.0)*n^2)) ); # G. C. Greubel, Oct 12 2019
|
|
CROSSREFS
|
|
|
KEYWORD
|
easy,nonn
|
|
AUTHOR
|
Joe K. Crump (joecr(AT)carolina.rr.com)
|
|
STATUS
|
approved
|
|
|
|