Smallest k such that 7^^n is not congruent to 7^^(n-1) mod k, where 7^^n denotes the power tower 7^7^...^7 (in which 7 appears n times).
A246495
Smallest k such that 7^^n is not congruent to 7^^(n-1) mod k, where 7^^n denotes the power tower 7^7^...^7 (in which 7 appears n times).
Terms
- a(0) =4a(1) =5a(2) =11a(3) =23a(4) =47a(5) =283a(6) =719a(7) =1439a(8) =2879a(9) =34549a(10) =138197a(11) =1266767a(12) =4782969a(13) =14348907
External references
- oeis: A246495