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A047901
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a(1) = 9; a(n+1) = a(n) * sum of decimal digits of a(n).
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9
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9, 81, 729, 13122, 118098, 3188646, 114791256, 4132485216, 148769467776, 10711401679872, 578415690713088, 41645929731342336, 2998506940656648192, 296852187125008171008, 24045027157125661851648, 2164052444141309566648320
(list;
graph;
refs;
listen;
history;
text;
internal format)
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OFFSET
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1,1
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LINKS
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FORMULA
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MATHEMATICA
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NestList[# Total[IntegerDigits[#]]&, 9, 20] (* Harvey P. Dale, Feb 07 2022 *)
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PROG
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(Haskell)
a047901 n = a047901_list !! (n-1)
(Python)
for _ in range(10**2):
....l *= sum(int(d) for d in str(l))
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CROSSREFS
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KEYWORD
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easy,nonn,base
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AUTHOR
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Miklos SZABO (mike(AT)ludens.elte.hu)
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EXTENSIONS
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STATUS
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approved
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