Number of fundamentally different graceful labelings of the n-cycle graph.

Terms

a(0) =1a(1) =1a(2) =0a(3) =0a(4) =6a(5) =12a(6) =0a(7) =0a(8) =104a(9) =246a(10) =0a(11) =0a(12) =3882a(13) =10282a(14) =0a(15) =0a(16) =212392a(17) =602270a(18) =0a(19) =0a(20) =16746039a(21) =53699700a(22) =0a(23) =0