Principal diagonal of the convolution array A213765.

Terms

a(0) =1a(1) =5a(2) =24a(3) =83a(4) =263a(5) =776a(6) =2201a(7) =6077a(8) =16488a(9) =44211a(10) =117615a(11) =311232a(12) =820641a(13) =2158645a(14) =5669096a(15) =14872483a(16) =38989367a(17) =102165928a(18) =267628569a(19) =700924525a(20) =1835493016a(21) =4806144675a(22) =12583939679a(23) =32947361088a(24) =86260987393a(25) =225840387941