a(1) = 4; for n>1, a(n) is the smallest square > a(n-1) obtained by inserting digits into a(n-1).

A068178

a(1) = 4; for n>1, a(n) is the smallest square > a(n-1) obtained by inserting digits into a(n-1).

Terms

    a(0) =4a(1) =49a(2) =1849a(3) =18496a(4) =1784896a(5) =177848896a(6) =17778488896

External references