Number of preferential arrangements of n labeled elements when at least k=4 elements per rank are required.

A232475

Number of preferential arrangements of n labeled elements when at least k=4 elements per rank are required.

Terms

    a(0) =1a(1) =0a(2) =0a(3) =0a(4) =1a(5) =1a(6) =1a(7) =1a(8) =71a(9) =253a(10) =673a(11) =1585a(12) =38149a(13) =277707a(14) =1402831a(15) =5923503a(16) =85577571a(17) =937629969a(18) =7475614341a(19) =48939413477a(20) =587610659505

External references