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Search: id:A053477
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| 1, 2, 5, 9, 7, 15, 9, 17, 14, 19, 13, 27, 15, 23, 24, 23, 19, 33, 21, 35, 30, 31, 25, 41, 30, 35, 36, 43, 31, 47, 33, 47, 42, 43, 44, 50, 39, 47, 48, 57, 43, 59, 45, 59, 60, 55, 49, 67, 54, 65, 60, 67, 55, 71, 64, 73, 66, 67, 61, 87, 63, 71, 78, 73, 74, 83, 69, 83, 78, 87, 73
(list; graph; listen)
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OFFSET
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1,2
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FORMULA
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a[n]=Sum[Nest[d, n, j], {j, 1, x[n]}], where summation goes until fixed point 2 is reached.
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EXAMPLE
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If n is prime then the iteration sequence is {p,2} and the sum is p+2. If n=30, then iterations of the d function are {30,8,4,3,2} and their sum is a(30)=47.
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MATHEMATICA
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g[n_] := DivisorSigma[0, n]; f[n_] := Plus @@ Drop[ FixedPointList[g, n], -1]; Table[ f[n], {n, 71}] (from Robert G. Wilson v Dec 16 2004)
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CROSSREFS
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Cf. A000005, A036452, A036453, A036454, A036455, A036459.
Sequence in context: A021389 A089578 A020852 this_sequence A104956 A020820 A111290
Adjacent sequences: A053474 A053475 A053476 this_sequence A053478 A053479 A053480
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KEYWORD
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nonn
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AUTHOR
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Labos E. (labos(AT)ana.sote.hu), Jan 14 2000
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