login
Number of n-bead necklaces labeled with numbers -2..2 not allowing reversal, with sum zero and three times sum of squares <= n*(2)*(2+1).
0

%I #6 Mar 12 2017 23:11:59

%S 1,2,5,15,59,187,753,3125,12503,54977,229533,1010861,4476937,19717931,

%T 89279611,400928643,1825710727,8356818535,38284519557,177041554325

%N Number of n-bead necklaces labeled with numbers -2..2 not allowing reversal, with sum zero and three times sum of squares <= n*(2)*(2+1).

%C Column 2 of A208814.

%e Some solutions for n=6:

%e .-1...-2...-2...-2...-2...-2...-1...-2...-2...-2...-2...-2...-2...-1...-1...-2

%e .-1...-1...-1....1....1....2...-1....1....0...-1....0...-1....1...-1...-1...-1

%e ..0....2....1....0....2...-1....2....1....1....1...-1....1....0....1....0....1

%e ..0....1....2....1...-1....0....0....1....0....2....2....1...-1....1....2....0

%e ..1...-1....1...-1....1....1...-1...-1....0...-1....1....2....2...-1...-1....0

%e ..1....1...-1....1...-1....0....1....0....1....1....0...-1....0....1....1....2

%K nonn

%O 1,2

%A _R. H. Hardin_, Mar 01 2012