OFFSET
1,5
LINKS
Hugo Pfoertner, Table of n, a(n) for n = 1..10000
PROG
(PARI) c=vectorsmall(2000000); for(x=1, 1000, my(x2=x*x); c[x2]++; c[x2+x2]++; for(y=1, x-1, my(y2=y*y); c[x2+y2]+=2));
a(n)=sum(k=ceil((1+(n-1)^2)/4), floor(n^2/4), c[k]);
for(k=1, 72, print1(a(k), ", "))
CROSSREFS
KEYWORD
nonn
AUTHOR
Hugo Pfoertner, Mar 26 2020
STATUS
approved