|
|
A106602
|
|
Number of primitive positive solutions to 8n+2=x^2+y^2.
|
|
2
|
|
|
1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 0, 1, 0, 1, 2, 0, 1, 0, 0, 2, 1, 0, 1, 1, 0, 1, 1, 0, 0, 1, 0, 0, 1, 0, 2, 1, 0, 1, 0, 0, 1, 1, 0, 1, 2, 0, 1, 1, 0, 2, 0, 0, 0, 2, 0, 1, 1, 0, 1, 0, 0, 0, 1, 0, 2, 1, 0, 1, 1, 0, 1, 1, 0
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
0,17
|
|
LINKS
|
|
|
EXAMPLE
|
a(16)=2 because we have 130=11^2+3^2=9^2+7^2. a(2)=0 because although 18=3^2+3^2, these components are not mutually prime.
|
|
MAPLE
|
local a, x, y, fourn;
fourn := 8*n+2 ;
a := 0 ;
for x from 1 do
if x^2 >= fourn then
return a;
else
y := fourn-x^2 ;
if issqr(y) then
y := sqrt(y) ;
if y <= x and igcd(x, y) = 1 then
a := a+1 ;
end if;
end if;
end if:
end do:
|
|
CROSSREFS
|
|
|
KEYWORD
|
easy,nonn
|
|
AUTHOR
|
|
|
STATUS
|
approved
|
|
|
|