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Number of distinct values of i*j + j*k + k*i with 1 <= i<= j < k <= n.
3

%I #4 Mar 14 2015 17:00:24

%S 0,1,4,10,19,33,49,70,96,127,161,201,238,287,337,390,449,519,586,662,

%T 741,818,902,997,1095,1194,1299,1410,1518,1651,1778,1908,2054,2186,

%U 2332,2493,2636,2793,2955,3128,3300,3481,3660,3840,4050,4252,4443,4665,4871

%N Number of distinct values of i*j + j*k + k*i with 1 <= i<= j < k <= n.

%t f[n_] := Length[ Union[ Flatten[ Table[i*j + j*k + k*i, {i, n}, {j, i, n}, {k, j + 1, n}]]]]; Table[ f[n], {n, 48}] (* _Robert G. Wilson v_, Jan 13 2005 *)

%Y Cf. A100439, A100440, A102533.

%K nonn

%O 1,3

%A _Robert G. Wilson v_, Jan 13 2005