a(n) = (40*100^n + 6*10^n - 1)/3.A350994a(n) = (40*100^n + 6*10^n - 1)/3.Terms a(0) =15a(1) =1353a(2) =133533a(3) =13335333a(4) =1333353333a(5) =133333533333External referencesoeis: A350994