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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.

User: Mark Bedaywi

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Mark Bedaywi has authored 1 sequences.

A334539 The eventual period of a sequence b(n, m) where b(n, 1) = 1 and the m-th term is the number of occurrences of b(n, m-1) in the list of integers from b(n, max(m-n, 1)) to b(n, m-1).

Original entry on oeis.org

1, 3, 8, 11, 25, 20, 40, 9, 45, 41, 158, 200, 14, 185, 636, 589, 595, 432, 773, 3196, 1249, 50, 7703, 7661, 12954, 25629, 14885, 41189, 23200, 87410, 33969, 63225, 20486, 212825, 58621, 152952, 135263, 2743830, 729008, 384150, 908629, 126746, 4543899, 3448777, 8531396
Offset: 1

Author

Mark Bedaywi, May 05 2020

Keywords

Comments

To generate the sequence b(n, m) for some n, start with the value 1 and then repeatedly append the number of times the last element of the sequence appears in the previous n terms. b(n, m) eventually becomes periodic for all n.
By the pigeonhole principle, a(n) has an upper bound of n^n.
The growth of a(n) appears to be roughly exponential.

Examples

			The sequence b(3, m) is 1, 1, 2, 1, 2, 2, 2, 3, 1, 1, 2, ... the period of which is 8.
The sequence b(4, m) is 1, 1, 2, 1, 3, 1, 2, 1, 2, 2, 3, 1, 1, 2, ... the period of which is 11.
The sequence b(5, m) is 1, 1, 2, 1, 3, 1, 3, 2, 1, 2, 2, 3, 1, 2, 3, 2, 2, 3, 2, 3, 2, 3, 3, 3, 4, 1, 1, 2, ... the period of which is 25.
		

Programs

  • Mathematica
    a[k_] := Block[{b = Append[0 Range@k, 1], A=<||>, n=0}, While[True, n++; b = Rest@ b; AppendTo[b, Count[b, b[[-1]]]]; If[ KeyExistsQ[A, b], Break[]]; A[b] = n]; n - A[b]]; Array[a, 30] (* Giovanni Resta, May 06 2020 *)
  • Python
    import sympy
    def A334539(n):
      return next(sympy.cycle_length(lambda x:x[1:]+(x.count(x[-1]),),(0,)*(n-1)+(1,)))[0] # Pontus von Brömssen, May 05 2021

Extensions

More terms from Giovanni Resta, May 06 2020