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A086356
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Fixed point if [nonzero-digit product]-function at initial-value=C[2n,n]=central binomial coefficient is iterated.
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0
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2, 6, 2, 7, 2, 4, 4, 2, 2, 6, 6, 6, 8, 6, 5, 8, 8, 4, 8, 2, 9, 8, 6, 8, 6, 2, 8, 8, 2, 8, 6, 2, 6, 6, 8, 2, 6, 6, 6, 8, 9, 2, 2, 8, 2, 8, 2, 8, 6, 4, 2, 2, 8, 8, 2, 8, 6, 8, 2, 8, 6, 8, 9, 6, 6, 2, 6, 2, 2, 2, 8, 6, 8, 6, 8, 2, 8, 8, 8, 8, 8, 8, 6, 2, 6, 2, 8, 6, 8, 8, 8, 8, 8, 6, 8, 8, 6, 8, 2, 8, 2, 8, 6, 8, 8
(list; graph; refs; listen; history; internal format)
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OFFSET
| 1,1
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FORMULA
| a(n)=A051802[A000984(n)]=fixed-point of A051801[C(2n, n)]
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EXAMPLE
| n=10, C[20,10]=184756, iteration list={184756,7560,210,2},
a(100)=2.
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MATHEMATICA
| prd[x_] := Apply[Times, DeleteCases[IntegerDigits[x], 0]] Table[FixedPoint[prd, Binomial[2*n, n]], {w, 1, 128}]
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CROSSREFS
| Cf. A051801, A051802, A086353-A086361, A029898, A010888, A038194, A000984.
Sequence in context: A170861 A078992 A062321 * A086359 A091944 A069936
Adjacent sequences: A086353 A086354 A086355 * A086357 A086358 A086359
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KEYWORD
| base,nonn
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AUTHOR
| Labos E. (labos(AT)ana.sote.hu), Jul 21 2003
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