69902domain: NAppears in sequencesa(1)=1, a(n)=a(n-1)+n^2 if n odd, a(n)=a(n-1)+ n^3 if n is even.at n=26A140149A Seidel matrix A(n,k) read by antidiagonals downwards.at n=58A323834A Seidel matrix A(n,k) read by antidiagonals downwards.at n=62A323834