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A135937
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a(1)=1. For n>=2, a(n) = product{d|a(n-1)} (d+1), where the product is over all positive divisors d of a(n-1).
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1
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OFFSET
| 1,2
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COMMENTS
| The next term is a lot bigger than 70000! and is too large to include. - Stefan Steinerberger (stefan.steinerberger(AT)gmail.com), Dec 31 2007
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EXAMPLE
| The positive divisors of a(3)=6 are 1,2,3,6. So a(4) = (1+1)*(2+1)*(3+1)*(6+1) = 2*3*4*7 = 168.
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MATHEMATICA
| a = {1}; Do[AppendTo[a, Times @@ (Divisors[a[[ -1]]] + 1)], {4}]; a - Stefan Steinerberger (stefan.steinerberger(AT)gmail.com), Dec 31 2007
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CROSSREFS
| Cf. A135938.
Sequence in context: A003189 A199482 A168649 * A137532 A072116 A203430
Adjacent sequences: A135934 A135935 A135936 * A135938 A135939 A135940
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KEYWORD
| nonn
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AUTHOR
| Leroy Quet Dec 07 2007
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EXTENSIONS
| a(5) from Stefan Steinerberger (stefan.steinerberger(AT)gmail.com), Dec 31 2007
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