Eighth diagonal of triangle A064094.

Terms

a(0) =1a(1) =429a(2) =14589a(3) =137089a(4) =702297a(5) =2537781a(6) =7312789a(7) =17981769a(8) =39322929a(9) =78571837a(10) =146150061a(11) =256488849a(12) =428947849a(13) =688828869a(14) =1068484677a(15) =1608522841a(16) =2359104609a(17) =3381338829a(18) =4748770909a(19) =6548966817