Number of n X 3 arrays with each row a permutation of 1..3 having at least as many downsteps as the preceding row, with rows in lexicographically nonincreasing order.

A222001

Number of n X 3 arrays with each row a permutation of 1..3 having at least as many downsteps as the preceding row, with rows in lexicographically nonincreasing order.

Terms

    a(0) =6a(1) =12a(2) =22a(3) =37a(4) =58a(5) =86a(6) =122a(7) =167a(8) =222a(9) =288a(10) =366a(11) =457a(12) =562a(13) =682a(14) =818a(15) =971a(16) =1142a(17) =1332a(18) =1542a(19) =1773a(20) =2026a(21) =2302a(22) =2602a(23) =2927a(24) =3278a(25) =3656a(26) =4062a(27) =4497a(28) =4962a(29) =5458

External references