Antidiagonal sums of table A122888.

Terms

a(0) =1a(1) =1a(2) =2a(3) =3a(4) =6a(5) =12a(6) =27a(7) =67a(8) =180a(9) =528a(10) =1676a(11) =5721a(12) =20924a(13) =81634a(14) =338322a(15) =1484209a(16) =6870492a(17) =33460830a(18) =170997842a(19) =914764494a(20) =5111445917a(21) =29773148141a(22) =180449216699