[go: up one dir, main page]
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!)
A086358 Digital root of n!. 3
1, 1, 2, 6, 6, 3, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9 (list; graph; refs; listen; history; text; internal format)
OFFSET
0,3
COMMENTS
a(n) = 9 for n >= 6.
LINKS
Table of n, a(n) for n=0..105.
Index entries for linear recurrences with constant coefficients, signature (1).
FORMULA
a(n) = A010888(n!) = fixed-point of A007953(n!). It equals n! modulo(9); at r = 0 use 9.
G.f.: (1 + x^2 + 4*x^3 - 3*x^5 + 6*x^6)/(1 - x). - Stefano Spezia, Jan 26 2023
EXAMPLE
n = 5, 5 != 120, iteration list = {120,3}, a(5) = 3.
MATHEMATICA
sud[x_] := Apply[Plus, DeleteCases[IntegerDigits[x], 0]]; Table[FixedPoint[sud, w!], {w, 1, 87}]
CROSSREFS
Cf. A000142, A086353-A086361, A007953, A010888, A038194, A029898, A004152.
Sequence in context: A153845 A105815 A136696 * A004152 A071678 A316164
Adjacent sequences: A086355 A086356 A086357 * A086359 A086360 A086361
KEYWORD
nonn,base,easy
AUTHOR
Labos Elemer, Jul 21 2003
EXTENSIONS
a(0) = 1 prepended by Alois P. Heinz, Dec 05 2018
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 August 29 09:16 EDT 2024. Contains 375511 sequences. (Running on oeis4.)