%I #6 Jul 16 2015 00:36:46
%S 0,0,1,4,10,20,31,48,70,96,123,161,197,240,293,340,394,460,524,596,
%T 670,744,819,918,1016,1112,1217,1322,1429,1561,1679,1798,1943,2072,
%U 2218,2379,2518,2669,2838,3009,3178,3361,3536,3713,3924,4120,4304,4522,4727
%N Number of distinct values of i*j + j*k + k*i with 1 <= i<j<k <= n.
%p f:=proc(n) local i,j,k,t1; t1:={}; for i from 1 to n-2 do for j from i+1 to n-1 do for k from j+1 to n do t1:={op(t1),i*j+j*k+k*i}; od: od: od: t1:=convert(t1,list); nops(t1); end;
%t f[n_] := Length[ Union[ Flatten[ Table[i*j + j*k + k*i, {i, n}, {j, i + 1, n}, {k, j + 1, n}] ]]]; Table[ f[n], {n, 49}] (* _Robert G. Wilson v_, Dec 14 2004 *)
%Y Cf. A027430, A100440, A102533, A102534.
%K nonn
%O 1,4
%A _N. J. A. Sloane_, Nov 21 2004
%E More terms from _Robert G. Wilson v_, Dec 14 2004