login
Number of n-bead necklaces labeled with numbers -5..5 allowing reversal, with sum zero and first differences in -5..5.
1

%I #10 Mar 13 2017 05:19:17

%S 1,3,7,38,187,1237,8235,58524,422504,3117158,23290361,176103500,

%T 1344136056,10344670554,80181862705,625395356182,4904914026691,

%U 38658468142298,306034794302017,2432316965565820,19401236375176220,155259190622702818

%N Number of n-bead necklaces labeled with numbers -5..5 allowing reversal, with sum zero and first differences in -5..5.

%H Andrew Howroyd, <a href="/A209029/b209029.txt">Table of n, a(n) for n = 1..50</a>

%e Some solutions for n=6:

%e .-4...-3...-2...-3...-3...-3...-3...-3...-3...-3...-3...-3...-2...-2...-2...-3

%e .-1....0...-1....0...-2....1....0...-2....1...-2...-2...-3....0....1....0...-2

%e ..0....1....0....0....1....2....3....2...-3....2....2...-2....1...-1....1....1

%e ..0....0....3....0....4...-2....0...-1....1....2....1....1....2....1....1....1

%e ..4....2...-1....1...-1....0...-2....2....2....3....0....5...-2....0...-2....3

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

%Y Column 5 of A209032.

%K nonn

%O 1,2

%A _R. H. Hardin_, Mar 04 2012

%E a(15)-a(22) from _Andrew Howroyd_, Mar 12 2017