Frequency of n-th largest distance in N times N times N grid, N > n.

Terms

a(0) =4a(1) =24a(2) =36a(3) =48a(4) =48a(5) =144a(6) =32a(7) =60a(8) =192a(9) =108a(10) =144a(11) =72a(12) =240a(13) =288a(14) =192a(15) =216a(16) =84a(17) =288a(18) =360a(19) =432a(20) =576a(21) =108a(22) =96a(23) =336a(24) =432a(25) =288a(26) =480a(27) =720a(28) =384a(29) =432