Number of possible states when placing n tokens of 2 alternating types on 3 piles.

A320731

Number of possible states when placing n tokens of 2 alternating types on 3 piles.

Terms

    a(0) =1a(1) =3a(2) =9a(3) =24a(4) =60a(5) =141a(6) =328a(7) =738a(8) =1647a(9) =3618a(10) =7893a(11) =17055a(12) =36619a(13) =78144a(14) =165888a(15) =350619a(16) =738012a(17) =1548279a(18) =3237611a(19) =6752439a(20) =14046525a(21) =29157612a(22) =60396996a(23) =124885167

External references