Guo-Niu Han [Sémin. Lothar. Comb. 85 (2021) B85c (electronic)] has introduced a new combinatorial object named standard puzzle. We use digraphs to show the relations between numbers in standard puzzles and propose a skeleton model. By this model, we solve the enumeration problem of over fifty thousand standard puzzle sequences. Most of them can be represented by classical numbers, such as Catalan numbers, double factorials, secant numbers and so on. Also, we prove several identities for standard puzzle sequences.
Citation: Shishuo Fu, Jiaxi Lu, Yuanzhe Ding. A skeleton model to enumerate standard puzzle sequences[J]. Electronic Research Archive, 2022, 30(1): 179-203. doi: 10.3934/era.2022010
Guo-Niu Han [Sémin. Lothar. Comb. 85 (2021) B85c (electronic)] has introduced a new combinatorial object named standard puzzle. We use digraphs to show the relations between numbers in standard puzzles and propose a skeleton model. By this model, we solve the enumeration problem of over fifty thousand standard puzzle sequences. Most of them can be represented by classical numbers, such as Catalan numbers, double factorials, secant numbers and so on. Also, we prove several identities for standard puzzle sequences.
[1] | R. P. Stanley, Catalan numbers, Cambridge University Press, 2015. |
[2] | D. André, Développement de $\sec x$ et $\tan x$, C. R. Math. Acad. Sci. Paris, 88 (1879), 965–979. |
[3] | R. C. Entringer, A combinatorial interpretation of the Euler and Bernoulli numbers, Nieuw Arch. Wisk. (3), 14 (1966), 241–246. |
[4] | D. Foata, G. N. Han, Doubloons and $q$-secant numbers, Münster J. Math., 3 (2010), 89–109. |
[5] | D. Foata, G. N. Han, Doubloons and new $q$-tangent numbers, Q. J. Math., 62 (2011), 417–432. https://doi.org/10.1093/qmath/hap043 doi: 10.1093/qmath/hap043 |
[6] | G. N. Han, Enumeration of standard puzzles, preprint, arXiv: 2006.14070. |
[7] | N. J. A. Sloane, The on-line encyclopedia of integer sequences, 1964. Available from: http://oeis.org/. |
[8] | D. Knuth, Whirlpool permutations, 2020. Available from: https://cs.stanford.edu/knuth/preprints.html. |
[9] | R. P. Stanley, Enumerative combinatorics, volume 1 second edition, Cambridge studies in advanced mathematics, 2011. |
[10] | G. Gasper, M. Rahman, Basic hypergeometric series, Cambridge University Press, 2004. https://doi.org/10.1017/cbo9780511526251.004 |
[11] | M. Petkovek, H. S. Wilf, D. Zeilberger, A = B. With a foreword by Donald E. Knuth., A K Peters, Ltd., Wellesley, (1996). |
[12] | Y. Gelineau, H. Shin, J. Zeng, Bijections for Entringer families, Eur. J. Comb., 32 (2011), 100–115. https://doi.org/10.1016/j.ejc.2010.07.004 doi: 10.1016/j.ejc.2010.07.004 |
[13] | H. Shin, J. Zeng, More bijections for Entringer and Arnold families, Electron. Res. Arch., 29 (2021), 2167–2185. https://doi.org/10.3934/era.2020111 doi: 10.3934/era.2020111 |
[14] | J. Cigler, A new class of q-Fibonacci polynomials, Electron. J. Comb., 1 (2003), R19. https://doi.org/10.1111/1468-0262.00406 doi: 10.1111/1468-0262.00406 |
[15] | N. J. Fine, Basic hypergeometric series and applications, American Mathematical Soc., (1988). |
[16] | D. Foata, G. N. Han, The $(t, q)$-analogs of secant and tangent numbers, Electron. J. Comb., 18 (2011). https://doi.org/10.37236/2003 |
[17] | J. M. Zhang, Z. X. Wen, W. Wu, Some properties of the Fibonacci sequence on an infinite alphabet. Electron. J. Comb., 24 (2017), P2–52. https://doi.org/10.37236/6745 |