A convolution triangle of numbers obtained from A025749.

Terms

a(0) =1a(1) =6a(2) =1a(3) =56a(4) =12a(5) =1a(6) =616a(7) =148a(8) =18a(9) =1a(10) =7392a(11) =1904a(12) =276a(13) =24a(14) =1a(15) =93632a(16) =25312a(17) =4080a(18) =440a(19) =30a(20) =1a(21) =1230592a(22) =344960a(23) =59808a(24) =7360a(25) =640a(26) =36a(27) =1a(28) =16612992a(29) =4792128