a(n) = -1 + A093137(n)^2.A098210a(n) = -1 + A093137(n)^2.Terms a(0) =0a(1) =15a(2) =1155a(3) =111555a(4) =11115555a(5) =1111155555a(6) =111111555555External referencesoeis: A098210