a(n) = (((5 - (n mod 2))*10^(3 + n*(9/2) - (n mod 2)*(5/2)))^2 + 2)/81.

A359846

a(n) = (((5 - (n mod 2))*10^(3 + n*(9/2) - (n mod 2)*(5/2)))^2 + 2)/81.

Terms

    a(0) =308642a(1) =1975308642

External references