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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A038553 Maximum cycle length in differentiation digraph for n-bit binary sequences.

Original entry on oeis.org

1, 1, 3, 1, 15, 6, 7, 1, 63, 30, 341, 12, 819, 14, 15, 1, 255, 126, 9709, 60, 63, 682, 2047, 24, 25575, 1638, 13797, 28, 475107, 30, 31, 1, 1023, 510, 4095, 252, 3233097, 19418, 4095, 120, 41943, 126, 5461, 1364, 4095, 4094, 8388607, 48, 2097151, 51150, 255, 3276, 3556769739, 27594, 1048575
Offset: 1

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Keywords

Comments

Length of longest cycle for vectors of length n under the Ducci map.
Also, the period of polynomial (x+1)^n+1 over GF(2) (cf. A046932). - Max Alekseyev, Oct 12 2013
Per the comment by T. D. Noe originally given in A138006, it appears that for an odd n > 1, a(n) <= n*(2^((n-1)/2)-1). - Max Alekseyev, Jul 10 2025

References

  • Simmons, G. J., The structure of the differentiation digraphs of binary sequences. Ars Combin. 35 (1993), A, 71-88. Math. Rev. 95f:05052.

Crossrefs

Formula

It appears that whenever b(n) = log2(a(n)/n + 1) is an integer and n > 1, b(n) = A119513(n) = A136043(n). - Andrei Zabolotskii, Jul 28 2025

Extensions

Entry revised by N. J. A. Sloane, Jun 19 2006, Feb 24 2008
a(46) corrected, terms a(51) onward and b-file added by Max Alekseyev, Oct 12 2013
b-file extended by Max Alekseyev, Sep 24 2019

A111944 Number of different lengths of cycles for vectors of length n under the Ducci map.

Original entry on oeis.org

1, 1, 2, 1, 2, 3, 2, 1, 3, 3, 2, 4, 2, 3, 4, 1, 3, 5, 2, 4, 5, 3, 2, 5, 3, 3, 4, 4, 2, 7, 2, 1, 4, 5, 6, 7, 2, 3, 6, 5, 3, 9, 2, 4, 9, 3, 2, 6, 3, 5, 4, 4, 2, 7, 6, 5, 4, 3, 2, 10, 2, 3, 6, 1, 5, 7, 2, 7, 6, 11, 2, 9, 3, 3, 7, 4, 6, 11, 2, 6, 5, 5, 2, 13, 6, 3, 5, 5, 2, 17, 5, 4, 6, 3, 6, 7, 3, 5, 7, 7
Offset: 1

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Author

N. J. A. Sloane, Nov 27 2005

Keywords

Comments

Total number of cycles is given by A135547.

Crossrefs

Cf. A038553.

Extensions

Terms a(1), a(2), and a(41) onward from Max Alekseyev, Oct 12 2013
Showing 1-2 of 2 results.