a(n) = A000670(n)^2.

A122725

a(n) = A000670(n)^2.

Terms

    a(0) =1a(1) =1a(2) =9a(3) =169a(4) =5625a(5) =292681a(6) =21930489a(7) =2236627849a(8) =297935847225

External references