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Fixed point if [nonzero-digit product]-function at initial-value=prime(n) is iterated.
1

%I #13 Sep 05 2019 03:24:10

%S 2,3,5,7,1,3,7,9,6,8,3,2,4,2,6,5,2,6,8,7,2,8,8,4,8,1,3,7,9,3,4,3,2,4,

%T 8,5,5,8,8,2,8,8,9,4,8,8,2,2,6,8,8,2,8,1,7,8,8,4,4,6,6,2,2,3,9,2,9,8,

%U 6,8,2,5,2,8,4,4,2,4,4,8,8,8,2,8,8,6,6,4,8,4,6,2,6,8,8,5,2,1,3,2,4,5,9,4,5

%N Fixed point if [nonzero-digit product]-function at initial-value=prime(n) is iterated.

%H Michael De Vlieger, <a href="/A086355/b086355.txt">Table of n, a(n) for n = 1..10000</a>

%F a(n) = A051802(A000040(n)) = fixed-point of A051801(n-th prime).

%e n=100, prime(100)=541, iteration list={541,20,2}, a(100)=2.

%t prd[x_] := Apply[Times, DeleteCases[IntegerDigits[x], 0]]; Table[FixedPoint[prd, Prime[w]], {w, 1, 128}]

%Y Cf. A051801, A051802, A086353-A086361, A029898, A010888, A038194.

%K base,nonn

%O 1,1

%A _Labos Elemer_, Jul 21 2003