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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

%I

%S 0,2,5,11,16,7,37,149,7,27,11,11,23,2389,49,11,31,19,67,109,13,8,25,8,

%T 461,179,1319,9,193,16,7,4931,121,7,9,8,7,8,2895630887,25,19,13,19,41,

%U 2209493509721,32,5939,23,43,11

%N a(n)=A082081[n! ]=A082081[A000142[n]] Fixed points of iterated A008475 function initiated at factorials as initial values.

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

%e a term from A000961.

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

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

%t 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}]

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

%K nonn

%O 1,2

%A _Labos Elemer_, Apr 08 2003

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Last modified January 27 23:50 EST 2020. Contains 331301 sequences. (Running on oeis4.)