cp's OEIS Frontend

A209338 Number of n-bead necklaces labeled with numbers -2..2 allowing reversal, with sum zero with no three beads in a row equal.

%I A209338 #6 Mar 12 2017 23:50:00
%S A209338 1,3,4,15,40,146,514,2032,8076,33310,138966,589618,2525494,10923868,
%T A209338 47599638,208824200,921391230,4086463748,18206487792
%N A209338 Number of n-bead necklaces labeled with numbers -2..2 allowing reversal, with sum zero with no three beads in a row equal.
%C A209338 Column 2 of A209344.
%e A209338 Some solutions for n=10:
%e A209338 .-2...-2...-2...-2...-2...-2...-2...-2...-2...-2...-2...-2...-2...-2...-2...-2
%e A209338 .-1...-2...-2...-1...-2...-1...-2...-1....0...-1....0...-1...-2...-1....0...-1
%e A209338 .-2....2....0...-1....1...-1....2....0....1...-1....1....0....1...-2....0...-1
%e A209338 .-1...-2....0....1....0....1...-2...-1....0....1....0....2....2....0...-1....1
%e A209338 ..0...-1...-1....2...-1....1....1....0....2....2...-2....0....1....2....2....2
%e A209338 ..2....0....1....1....2....0....2....2....0....0....1...-1....2....1...-2....2
%e A209338 ..1....2....2....0...-1....0....0...-1...-1....0...-2....0...-2....1....0....0
%e A209338 ..1...-1...-1....1....0....2...-2....1....1...-2....1....2...-1...-1....0...-1
%e A209338 ..0....2....2....0....1...-2....1....2...-2....1....1...-1...-1....0....1...-2
%e A209338 ..2....2....1...-1....2....2....2....0....1....2....2....1....2....2....2....2
%K A209338 nonn
%O A209338 1,2
%A A209338 _R. H. Hardin_, Mar 06 2012