A convolution triangle of numbers obtained from A025750.

Terms

a(0) =1a(1) =10a(2) =1a(3) =150a(4) =20a(5) =1a(6) =2625a(7) =400a(8) =30a(9) =1a(10) =49875a(11) =8250a(12) =750a(13) =40a(14) =1a(15) =997500a(16) =174750a(17) =17875a(18) =1200a(19) =50a(20) =1a(21) =20662500a(22) =3780000a(23) =419625a(24) =32500a(25) =1750a(26) =60a(27) =1a(28) =439078125a(29) =83128125