A374714 - OEIS

%I #11 Jul 18 2024 14:27:36

%S 1,5,15,35,70,119,202,317,473,671,902,1138,1515,2008,2521,3039,3758,

%T 4592,5539,6657,7879,9209,10797,12304,14243,16371,18348,21006,23816,

%U 26563,29848,33046,36698,40190,44885,49068,54040,59479,64762,70420,76810,83414,90659,98158,105838,114127,123048

%N Number of distinct sums i^3 + j^3 + k^3 + l^3 for 1<=i<=j<=k<=l<=n.

%o (PARI) a(n) = my(v=vector(4*n^3)); for(i=1, n, for(j=i, n, for(k=j, n, for(l=k, n, v[i^3+j^3+k^3+l^3]+=1)))); sum(i=1, #v, v[i]>0);

%o (Python)

%o def A374714(n): return len({i**3+j**3+k**3+l**3 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 18 2024

%Y Cf. A061791, A374713.

%Y Cf. A374711, A374716.

%K nonn

%O 1,2

%A _Seiichi Manyama_, Jul 17 2024