1220703124

Appears in sequences

• a(n) = 5^n - 1.at n=13A024049
• a(n) = 4*a(n-1) + 5*a(n-2) for n > 1, with a(0) = 2 and a(1) = 4.at n=13A087404
• a(n) = 0^n + 5^n - 1.at n=13A103455
• Minimum m coprime to 5 such that the convergence speed of m^^m := m^(m^^(m-1)) is equal to n >= 0, where A317905(n) represents the convergence speed of m^^m (and m = A047201(n), the n-th non-multiple of 5).at n=13A337833
• The "Fouriest" numbers: numbers that can be expressed as a string of 4's longer than the original number in some base.at n=24A349031