Number of Young tableaux of height <= 5.

Terms

a(0) =1a(1) =1a(2) =2a(3) =4a(4) =10a(5) =26a(6) =75a(7) =225a(8) =715a(9) =2347a(10) =7990a(11) =27908a(12) =99991a(13) =365587a(14) =1362310a(15) =5159208a(16) =19831101a(17) =77233517a(18) =304423574a(19) =1212962072a(20) =4881181036a(21) =19821471956a(22) =81165639197a(23) =334925706659