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%I #2 Mar 30 2012 18:34:45
%S 480,504,560,576,630,672,720,792,840,960,1320,1350,1440,1512,1530,
%T 1680,1950,2450,2520,4290
%N Numbers abc such that (a+2)(b+2)(c+2)=2abc.
%C There are 20 rectangular parallelepipeds with integer edges such that increasing each edge by 2 doubles the volume, sorted in increasing volume: {6,8,10}, {6,7,12}, {5,8,14}, {6,6,16}, {5,7,18}, {4,12,14}, {4,10,18}, {4,9,22}, {5,6,28}, {4,8,30}, {3,20,22}, {3,18,25}, {3,16,30}, {4,7,54}, {3,15,34}, {3,14,40}, {3,13,50}, {5,5,98}, {3,12,70}, {3,11,130}
%e The third smallest product of abc such that (a+2)(b+2)(c+2)=2abc is 560, so a(3)=560.
%K fini,full,nonn
%O 1,1
%A _Graeme McRae_, Jan 14 2006
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