OFFSET
1,2
PROG
(PARI) a(n) = my(v=vector(4*n^2)); for(i=1, n, for(j=i, n, for(k=j, n, for(l=k, n, v[i^2+j^2+k^2+l^2]+=1)))); sum(i=1, #v, v[i]>0);
(Python)
def A374716(n): return len({i**2+j**2+k**2+l**2 for i in range(1, n+1) for j in range(i, n+1) for k in range(j, n+1) for l in range(k, n+1)}) # Chai Wah Wu, Jul 17 2024
CROSSREFS
KEYWORD
nonn
AUTHOR
Seiichi Manyama, Jul 17 2024
STATUS
approved