Fourth accumulation array of A051340, by antidiagonals.

Terms

a(0) =1a(1) =5a(2) =6a(3) =15a(4) =29a(5) =21a(6) =35a(7) =85a(8) =99a(9) =56a(10) =70a(11) =195a(12) =285a(13) =259a(14) =126a(15) =126a(16) =385a(17) =645a(18) =735a(19) =574a(20) =252a(21) =210a(22) =686a(23) =1260a(24) =1645a(25) =1610a(26) =1134a(27) =462a(28) =330a(29) =1134