Total number of graceful labelings of the n-pan graph.

Terms

a(0) =20a(1) =32a(2) =52a(3) =120a(4) =240a(5) =640a(6) =1576a(7) =3696a(8) =9736a(9) =28712a(10) =85784a(11) =232960a(12) =693704a(13) =2182032a(14) =7049008a(15) =22514960a(16) =74484552a(17) =259871472