The OEIS mourns the passing of Jim Simons and is grateful to the Simons Foundation for its support of research in many branches of science, including the OEIS.
The OEIS is supported by the many generous donors to the OEIS Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A332242 Numbers k such that k! has exactly k nonzero decimal digits. 0
 1, 48, 49, 53, 54, 57 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS No other terms < 100000. Conjecture: these 6 terms are the only terms of the sequence, i.e., there are no terms larger than 57. LINKS Table of n, a(n) for n=1..6. FORMULA { k : A034886(k) - A027869(k) = k }. EXAMPLE 48! = 12413915592536072670862289047373375038521486354677760000000000 has 48 nonzero decimal digits, so 48 is a term. MAPLE q:= n-> nops(subs(0=NULL, convert(n!, base, 10)))=n: select(q, [\$0..100])[]; # Alois P. Heinz, Feb 07 2020 PROG (Python) A332242_list, i, n = [], 0, 1 while i < 1000: s = str(n) if len(s) - s.count('0') == i: A332242_list.append(i) i += 1 n *= i (PARI) isok(k) = #select(x->(x != 0), digits(k!)) == k; \\ Michel Marcus, Feb 08 2020 CROSSREFS Cf. A000142, A027869, A034886. Sequence in context: A165869 A121377 A327894 * A296872 A364702 A357429 Adjacent sequences: A332239 A332240 A332241 * A332243 A332244 A332245 KEYWORD nonn,base AUTHOR Chai Wah Wu, Feb 07 2020 STATUS approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified May 19 00:35 EDT 2024. Contains 372666 sequences. (Running on oeis4.)