Left diagonal of partition triangle A047812.

Terms

a(0) =0a(1) =0a(2) =1a(3) =7a(4) =20a(5) =48a(6) =100a(7) =194a(8) =352a(9) =615a(10) =1034a(11) =1693a(12) =2705a(13) =4239a(14) =6522a(15) =9889a(16) =14786a(17) =21844a(18) =31913a(19) =46165a(20) =66162a(21) =94035a(22) =132600a(23) =185637a(24) =258128a(25) =356674a(26) =489906a(27) =669173a(28) =909212a(29) =1229217