a(n) = (10^n)^2 + 4*(10^n) + 1.A225810a(n) = (10^n)^2 + 4*(10^n) + 1.Terms a(0) =6a(1) =141a(2) =10401a(3) =1004001a(4) =100040001a(5) =10000400001External referencesoeis: A225810