The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 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 FORMULA a(n) = A010888(n!) = fixed-point of A007953(n!). It equals n! modulo(9); at r = 0 use 9. 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, 128}] 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 | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified September 21 03:13 EDT 2020. Contains 337266 sequences. (Running on oeis4.)