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A047897
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a(1) = 5; for n > 0, a(n+1) = a(n) * sum of digits of a(n).
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11
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5, 25, 175, 2275, 36400, 473200, 7571200, 166566400, 5663257600, 226530304000, 5663257600000, 226530304000000, 5663257600000000, 226530304000000000, 5663257600000000000, 226530304000000000000, 5663257600000000000000
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OFFSET
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1,1
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COMMENTS
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After a(9), every second element has the same beginning. a(11+2k) = 40 * a(10+2k) = 40 * 25 * a(9+2k).
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LINKS
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FORMULA
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MATHEMATICA
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NestList[#*Total[IntegerDigits[#]]&, 5, 20] (* Harvey P. Dale, Jan 25 2014 *)
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PROG
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(Haskell)
a047897 n = a047897_list !! (n-1)
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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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STATUS
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approved
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