%I
%S 10,21,36,78,210
%N Sum of number of pips on dice in shape of Platonic solids.
%C This is obviously a finite sequence, since there are only five Platonic solids.
%H Wikipedia, <a href="http://en.wikipedia.org/wiki/Dice">Dice</a>.
%e The third number in the sequence is 36 because the third Platonic solid has eight faces and the pips on an eightfaced die add up to 36 [by sum_1^n(n) = 1/2 * n * (n+1), so 1/2 * 8 * 9 = 36 for n = 8].
%t # (# + 1)/2 & /@ {4, 6, 8, 12, 20} (* _Robert G. Wilson v_, Apr 18 2008 *)
%o (Perl) for $n (4, 6, 8, 12, 20) { print $n*($n+1)/2 }
%Y Cf. A053016.
%K fini,full,nonn
%O 1,1
%A _Philip Newton_, Aug 09 2001
