Number of n X 4 arrays with each row a permutation of 1..4 having at least as many downsteps as the preceding row, with rows in lexicographically nonincreasing order.
A222002
Number of n X 4 arrays with each row a permutation of 1..4 having at least as many downsteps as the preceding row, with rows in lexicographically nonincreasing order.
Terms
- a(0) =24a(1) =157a(2) =704a(3) =2470a(4) =7328a(5) =19228a(6) =45894a(7) =101543a(8) =211070a(9) =416275a(10) =784864a(11) =1423138a(12) =2493494a(13) =4238102a(14) =7010394a(15) =11316307a(16) =17867564a(17) =27649657a(18) =42007616a(19) =62753110a(20) =92296932a(21) =133811472a(22) =191428382a(23) =270477287a(24) =377772098a(25) =521952239a(26) =713886912
External references
- oeis: A222002