A082086 Fixed points when A001414 is iterated and started at factorials of prime numbers.

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

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-François Alcover, May 06 2017 *)

Crossrefs

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

Sequence in context: A078576 A256302 A205396 * A082084 A094236 A340777

Adjacent sequences: A082083 A082084 A082085 * A082087 A082088 A082089

Keyword

nonn

Author

Labos Elemer, Apr 08 2003

Status

approved