Three transcendental numbers from the last non-zero digits of \(n^n\), \(F_n\), and \(n!\). (English) Zbl 1165.11060
Consider the function \(\text{lnzd}(M)\) returning the last nonzero digit of a positive integer \(M\) in base \(10\). For an integer sequence \(\{s_n\}\) let \(A(\{s_n\})\) be the number with decimal expansion \(0.d_1d_2d_3\dots\) where \(d_j=\text{lnzd}(s_j)\). In [”Two irrational numbers from the last nonzero digits of \(n!\) and \(n^n\),” Math. Mag. 74, No. 4, 316–320 (2001; Zbl 1031.11002)] the author proves that the numbers \(A(\{n!\})\) and \(A(\{n^n\})\) are irrational and that the digits of these numbers exhibit patterns on many scales. In the present paper the author uses these patterns to prove that the numbers \(A(\{n!\})\) and \(A(\{n^n\})\) are transcendental. The author also proves that if \(\{F_n\}\) is the Fibonacci sequence then the sequence \(\{\text{lnzd}(F_n)\}\) have some pattern and the number \(A(\{F_n\})\) is transcendental.
Reviewer: Jan Šustek
MSC:
11J81 | Transcendence (general theory) |
11B39 | Fibonacci and Lucas numbers and polynomials and generalizations |
Citations:
Zbl 1031.11002Online Encyclopedia of Integer Sequences:
a(n) = Fibonacci(n) mod 10.a(n) is the final nonzero digit of n!.
Final digit of n^n.
Final nonzero digit of n^n.
Last nonzero digit of A000043(n)!.