login
This site is supported by donations to The OEIS Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A082086 Fixed points when A001414 is iterated and started at factorials of prime numbers. 2
2, 5, 5, 5, 13, 23, 61, 19, 5, 283, 5, 23, 13, 29, 7, 61, 947, 29, 137, 11, 353, 23, 199, 5, 47, 2381, 5, 103, 359, 13, 5, 5, 7, 5, 47, 19, 577, 7, 5, 29, 5, 5, 5, 41, 11, 23, 239, 7, 11, 5, 11, 5, 23, 11821, 31, 5, 5, 13669, 7, 193, 5, 991, 89, 7, 13, 18199, 131, 113, 20849 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Table of n, a(n) for n=1..69.

FORMULA

a(n) = A029908(A000142(A000040(n)) = A029908(prime(n)!).

EXAMPLE

n=100, prime(100) = 541, start at 541!, the list is: {541!,...,46374,195,21,10,7} so a(100)=7.

MATHEMATICA

sopfr[n_] := Total[Times @@@ FactorInteger[n]]; a[n_] := FixedPoint[sopfr, Prime[n]!]; Array[a, 100] (* Jean-Fran├žois Alcover, May 06 2017 *)

CROSSREFS

Cf. A008475, A082081, A000142, A000040, A000961.

Sequence in context: A078576 A256302 A205396 * A082084 A094236 A205444

Adjacent sequences:  A082083 A082084 A082085 * A082087 A082088 A082089

KEYWORD

nonn

AUTHOR

Labos Elemer, Apr 08 2003

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.

License Agreements, Terms of Use, Privacy Policy. .

Last modified November 15 18:29 EST 2019. Contains 329149 sequences. (Running on oeis4.)