Number of inequivalent ways to color vertices of a cube using at most n colors.

Terms

a(0) =0a(1) =1a(2) =23a(3) =333a(4) =2916a(5) =16725a(6) =70911a(7) =241913a(8) =701968a(9) =1798281a(10) =4173775a(11) =8942021a(12) =17930628a(13) =34009053a(14) =61518471a(15) =106823025a(16) =179003456a(17) =290715793a(18) =459239463a(19) =707740861a(20) =1066780100a(21) =1576090341a(22) =2286660783a(23) =3263156073a(24) =4586706576