Number of ways to color edges of a tetrahedron using <= n colors.

Terms

a(0) =0a(1) =1a(2) =12a(3) =87a(4) =416a(5) =1475a(6) =4236a(7) =10437a(8) =22912a(9) =45981a(10) =85900a(11) =151371a(12) =254112a(13) =409487a(14) =637196a(15) =962025a(16) =1414656a(17) =2032537a(18) =2860812a(19) =3953311a(20) =5373600a(21) =7196091a(22) =9507212a(23) =12406637a(24) =16008576a(25) =20443125a(26) =25857676a(27) =32418387a(28) =40311712