Let F(n) = 2^(2^n) + 1 = the n-th Fermat number, M(n) = 2^n - 1 = the n-th Mersenne number. Then a(n) = F(n) - M(n) + 1 = 2^(2^n) + 1 - (2^n - 1) + 1 = 2^(2^n) - 2^n + 3.
A119562
Let F(n) = 2^(2^n) + 1 = the n-th Fermat number, M(n) = 2^n - 1 = the n-th Mersenne number. Then a(n) = F(n) - M(n) + 1 = 2^(2^n) + 1 - (2^n - 1) + 1 = 2^(2^n) - 2^n + 3.
Terms
- a(0) =4a(1) =5a(2) =15a(3) =251a(4) =65523a(5) =4294967267
External references
- oeis: A119562