cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

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A182006 Lengths of periods of iterations described in A182005 for terms of A182005.

Original entry on oeis.org

2, 3, 2, 2, 3, 2, 3, 2, 2, 2, 3, 2, 2, 2, 2, 3, 3, 3, 2, 3, 2, 2, 3, 2, 2, 2, 4, 2, 2, 2, 2, 2, 2, 3, 2, 2, 2, 3, 2, 2, 2, 3, 2, 2, 2, 3, 3, 2, 2, 2, 3, 2, 2, 2, 2, 2, 3, 3, 3, 2, 2, 2, 2, 3, 2, 2, 2, 2, 2, 2, 2, 3, 2, 2, 2, 3, 2, 2, 2, 2, 3, 2, 3, 3, 2, 2, 3, 2, 2, 2, 2, 3, 2, 2, 2, 3, 2, 3
Offset: 1

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Period of length 4 occurs for terms of A182005 equaled 91, 405, 659, 873, 1335, 1723, 1751,... For example, for 91 we have period {52, 50, 60, 54}. Up to now, periods of lengths 5 or 6 were not found.

Crossrefs

Cf. A182005.

Programs

  • Mathematica
    period[seq_] := (If[Last[#1] == {} || Length[#1] == Length[seq] -1, 0, Length[#1]]&)[NestWhileList[Rest, Rest[seq], #1 != Take[seq, Length[#1]]&, 1]]; {A182005, A182006} = Transpose[Select[Table[{n, period[Take[Module[{p}, Flatten[{p=Apply[Plus, IntegerDigits[2^#, 3]], Table[p=Apply[Plus, IntegerDigits[2^#+p,3]], {40}]}&[n]]], -20]]}, {n,1,500}], #[[2]] =!= 1&]]
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