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A077353
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a(n) = (concatenation in ascending order of divisors of 5^n)/5^n.
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2
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1, 3, 61, 12201, 2440201, 4880402001, 97608040020001, 1952160800400020001, 390432160080004000200001, 780864320160008000400002000001, 1561728640320016000800004000002000001, 31234572806400320016000080000040000020000001
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OFFSET
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0,2
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LINKS
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FORMULA
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a(0) = 1, a(n+1)) = 2*10^n*a(n) + 1.
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EXAMPLE
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a(5) = 15251256253125/3125 = 4880402001.
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PROG
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(PARI) a(n) = eval(concat(apply(x->Str(x), divisors(5^n))))/5^n \\ Max Alekseyev, Dec 12 2011
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CROSSREFS
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KEYWORD
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base,nonn
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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