Antidiagonal sums of the convolution array A213505.

Terms

a(0) =1a(1) =12a(2) =68a(3) =260a(4) =777a(5) =1960a(6) =4368a(7) =8856a(8) =16665a(9) =29524a(10) =49764a(11) =80444a(12) =125489a(13) =189840a(14) =279616a(15) =402288a(16) =566865a(17) =784092a(18) =1066660a(19) =1429428a(20) =1889657a(21) =2467256a(22) =3185040a(23) =4069000a(24) =5148585a(25) =6456996a(26) =8031492a(27) =9913708a(28) =12149985a(29) =14791712