Convolution of Bell numbers with themselves.

Terms

a(0) =1a(1) =2a(2) =5a(3) =14a(4) =44a(5) =154a(6) =595a(7) =2518a(8) =11591a(9) =57672a(10) =308368a(11) =1762500a(12) =10716321a(13) =69011130a(14) =468856113a(15) =3348695194a(16) =25064539520a(17) =196052415230