Dear sir, > In my opinion A325799 does not give the signature exitation (called > "siex" in the sequel) of n. For instance : A325799(9) = 2, while the siex of 9 is 1 A325799(20) = 0 while the siex of 20 is 1 And there are many other counter examples. Sincere greetings. Emmanuel Vantieghem.