Square of infinite lower triangular matrix A078122.

Terms

a(0) =1a(1) =2a(2) =1a(3) =5a(4) =6a(5) =1a(6) =23a(7) =51a(8) =18a(9) =1a(10) =239a(11) =861a(12) =477a(13) =54a(14) =1a(15) =5828a(16) =32856a(17) =25263a(18) =4347a(19) =162a(20) =1a(21) =342383a(22) =3013980a(23) =3016107a(24) =699813a(25) =39285a(26) =486a(27) =1a(28) =50110484a(29) =690729981