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.
login
The OEIS is supported by the many generous donors to the OEIS Foundation.

 

Logo
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
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
Sequence in context: A165869 A121377 A327894 * A296872 A364702 A357429
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.

License Agreements, Terms of Use, Privacy Policy. .

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