Number of ways of placing n labeled balls into 3 indistinguishable boxes with at least 2 balls in each box.

A000478

Number of ways of placing n labeled balls into 3 indistinguishable boxes with at least 2 balls in each box.

Terms

    a(0) =15a(1) =105a(2) =490a(3) =1918a(4) =6825a(5) =22935a(6) =74316a(7) =235092a(8) =731731a(9) =2252341a(10) =6879678a(11) =20900922a(12) =63259533a(13) =190957923a(14) =575363776a(15) =1731333808a(16) =5205011031a(17) =15638101281a(18) =46962537810a(19) =140988276150a(20) =423174543025

External references