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A086354
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Fixed point if [nonzero-digit product]-function at initial-value=2^n is iterated.
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2
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2, 4, 8, 6, 6, 8, 6, 6, 1, 8, 8, 2, 6, 2, 2, 4, 8, 2, 1, 6, 2, 2, 6, 8, 2, 8, 2, 8, 2, 2, 8, 6, 6, 2, 2, 6, 2, 2, 6, 8, 8, 6, 3, 4, 2, 2, 6, 6, 2, 8, 6, 2, 2, 9, 8, 6, 6, 5, 8, 2, 8, 8, 2, 6, 2, 8, 8, 8, 5, 8, 8, 8, 2, 8, 6, 4, 8, 6, 2, 7, 1, 8, 8, 4, 2, 8, 8
(list; graph; refs; listen; history; internal format)
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OFFSET
| 1,1
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LINKS
| Nathaniel Johnston, Table of n, a(n) for n = 1..10000
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FORMULA
| a(n)=A051802[2^n]=fixed-point of A051801[2^n]
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EXAMPLE
| n=20, 2^20=1048576, iteration list={1048576,6720,84,32,6},
a(10)=6.
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MAPLE
| A051801 := proc(n) local d, j: d:=convert(n, base, 10): return mul(`if`(d[j]=0, 1, d[j]), j=1..nops(d)): end: A086354 := proc(n) local m: m:=2^n: while(length(m)>1)do m:=A051801(m): od: return m: end: seq(A086354(n), n=1..100); # Nathaniel Johnston, May 04 2011
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MATHEMATICA
| prd[x_] := Apply[Times, DeleteCases[IntegerDigits[x], 0]] Table[FixedPoint[prd, 2^w], {w, 1, 128}]
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CROSSREFS
| Cf. A051801, A051802, A086353-A086361, A029898, A010888.
Sequence in context: A103546 A080868 A046260 * A014257 A138284 A175156
Adjacent sequences: A086351 A086352 A086353 * A086355 A086356 A086357
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KEYWORD
| base,easy,nonn
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AUTHOR
| Labos E. (labos(AT)ana.sote.hu), Jul 21 2003
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