Number of ways of placing n balls into boxes 1,2,... in such a way that any two adjacent boxes contain at least 4 balls.

A257666

Number of ways of placing n balls into boxes 1,2,... in such a way that any two adjacent boxes contain at least 4 balls.

Terms

    a(0) =1a(1) =1a(2) =1a(3) =1a(4) =7a(5) =11a(6) =17a(7) =25a(8) =51a(9) =94a(10) =165a(11) =280a(12) =496a(13) =887a(14) =1576a(15) =2770a(16) =4880a(17) =8630a(18) =15276a(19) =26990a(20) =47656a(21) =84183a(22) =148781a(23) =262921a(24) =464528a(25) =820699a(26) =1450091a(27) =2562250a(28) =4527272a(29) =7999104

External references