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A082083 a(n)=A082081[n! ]=A082081[A000142[n]] Fixed points of iterated A008475 function initiated at factorials as initial values. 5
0, 2, 5, 11, 16, 7, 37, 149, 7, 27, 11, 11, 23, 2389, 49, 11, 31, 19, 67, 109, 13, 8, 25, 8, 461, 179, 1319, 9, 193, 16, 7, 4931, 121, 7, 9, 8, 7, 8, 2895630887, 25, 19, 13, 19, 41, 2209493509721, 32, 5939, 23, 43, 11 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Table of n, a(n) for n=1..50.

EXAMPLE

Fixed point is always a prime or a true power of prime:

a term from A000961.

n=20!=2432902008176640000, a(20)=109 because

fixed point list={2432902008176640000,269439,214,109}}

MATHEMATICA

ffi[x_] := Flatten[FactorInteger[x]] lf[x_] := Length[FactorInteger[x]] ba[x_] := Table[Part[ffi[x], 2*w-1], {w, 1, lf[x]}] ep[x_] := Table[Part[ffi[x], 2*w], {w, 1, lf[x]}] sex[x_] := Apply[Plus, ba[x]^ep[x]] Table[FixedPoint[sex, w! ], {w, 1, 128}]

CROSSREFS

Cf. A001414, A056239, A008475, A082081-A082084, A000961, A000142.

Sequence in context: A206602 A238159 A080156 * A287558 A024917 A081402

Adjacent sequences:  A082080 A082081 A082082 * A082084 A082085 A082086

KEYWORD

nonn

AUTHOR

Labos Elemer, Apr 08 2003

STATUS

approved

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Last modified December 10 18:10 EST 2019. Contains 329901 sequences. (Running on oeis4.)