%I #8 Dec 11 2020 08:07:55
%S 308,1916,9572,20732,43148,73052,155156,219716,331892,440036
%N Number of 3 X 3 integer matrices with elements in the range [ -n,n ] which represent a three-fold rotation.
%F A053170(n) = 2 * (1 + A053171(n) + a(n) + A053173(n) + A053174(n)).
%Y Cf. A053170, A053171, A053173, A053174.
%K nonn,more
%O 1,1
%A _Ralf W. Grosse-Kunstleve_, Mar 26 2000