Triangular array (a Riordan array) related to tennis ball problem, read by rows.

Terms

a(0) =1a(1) =0a(2) =1a(3) =1a(4) =1a(5) =1a(6) =0a(7) =3a(8) =2a(9) =1a(10) =6a(11) =6a(12) =6a(13) =3a(14) =1a(15) =0a(16) =22a(17) =16a(18) =10a(19) =4a(20) =1a(21) =53a(22) =53a(23) =53a(24) =31a(25) =15a(26) =5a(27) =1a(28) =0a(29) =211