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.
%I A051255 #74 Feb 19 2025 12:20:28 %S A051255 1,1,2,11,170,7429,920460,323801820,323674802088,919856004546820, %T A051255 7434724817843114428,170943292930264547814443, %U A051255 11183057455425265737399150652,2081853548182272792243789109645876 %N A051255 Number of cyclically symmetric transpose complement plane partitions in a 2n X 2n X 2n box. %C A051255 Hankel transform of A006013 without initial term is this sequence without initial term. - _Michael Somos_, May 15 2022 %D A051255 D. M. Bressoud, Proofs and Confirmations, Camb. Univ. Press, 1999; Eq. (6.15), p. 199 (corrected). %H A051255 Vincenzo Librandi, <a href="/A051255/b051255.txt">Table of n, a(n) for n = 0..60</a> %H A051255 Paul Barry, <a href="https://cs.uwaterloo.ca/journals/JIS/VOL19/Barry/barry321.html">Jacobsthal Decompositions of Pascal's Triangle, Ternary Trees, and Alternating Sign Matrices</a>, Journal of Integer Sequences, 19, 2016, #16.3.5. %H A051255 Paul Barry, <a href="https://arxiv.org/abs/1912.11845">Chebyshev moments and Riordan involutions</a>, arXiv:1912.11845 [math.CO], 2019. %H A051255 Paul Barry, <a href="https://doi.org/10.3390/math13020242">Extensions of Riordan Arrays and Their Applications</a>, Mathematics (2025) Vol. 13, No. 2, 242. See p. 24. %H A051255 M. T. Batchelor, J. de Gier and B. Nienhuis, <a href="http://arXiv.org/abs/cond-mat/0101385">The quantum symmetric XXZ chain at Delta=-1/2, alternating sign matrices and plane partitions</a>, arXiv:cond-mat/0101385 [cond-mat.stat-mech], 2001. See N_8(2n). %H A051255 D. M. Bressoud, <a href="https://www.macalester.edu/~bressoud/books/PnC/PnCcorrect.html">Corrections: Proofs and Confirmations</a> %H A051255 N. T. Cameron, <a href="https://web.archive.org/web/20190331234929/https://www.math.hmc.edu/~cameron/dissertation.pdf">Random walks, trees and extensions of Riordan group techniques</a>, Dissertation, Howard University, 2002. %H A051255 Naiomi Cameron and J. E. McLeod, <a href="https://cs.uwaterloo.ca/journals/JIS/VOL19/McLeod/mcleod3.html">Returns and Hills on Generalized Dyck Paths</a>, Journal of Integer Sequences, Vol. 19, 2016, #16.6.1. %H A051255 J. de Gier, <a href="https://arxiv.org/abs/math/0211285">Loops, matchings and alternating-sign matrices</a>, arXiv:math/0211285 [math.CO], 2002. %H A051255 I. Gessel and G. Xin, <a href="https://arxiv.org/abs/math/0505217">The generating function of ternary trees and continued fractions</a>, arXiv:math/0505217 [math.CO], 2005. %H A051255 Anatol N. Kirillov, <a href="https://doi.org/10.3842/SIGMA.2016.034">Notes on Schubert, Grothendieck and key polynomials</a>, SIGMA, Symmetry Integrability Geom. Methods Appl. 12, Paper 034, 56 p. (2016). %H A051255 Yaping Liu, <a href="http://www.ripublication.com/gjpam22/gjpamv18n1_05.pdf">On the Recursiveness of Pascal Sequences</a>, Global J. of Pure and Appl. Math. (2022) Vol. 18, No. 1, 71-80. %F A051255 a(n) ~ exp(1/72) * GAMMA(1/3)^(2/3) * n^(7/72) * 3^(3*n^2 - 3*n/2 + 11/72) / (A^(1/6) * Pi^(1/3) * 2^(4*n^2 - n - 1/18)), where A = A074962 = 1.2824271291... is the Glaisher-Kinkelin constant. - _Vaclav Kotesovec_, Feb 28 2015 %F A051255 a(n) = Product_{i=0..n-1} (3i+1) C(6i,2i)/(C(4i+1,2i)*(2i+1)), using [Bressoud, Corrections, p. 199: N8]. - _M. F. Hasler_, Oct 04 2018 %e A051255 For n=0 there is the empty partition by convention so a(0)=1. For n=1 there is a single cyclically symmetric transpose complement plane partition in a 2 X 2 X 2 box so a(1)=1. %e A051255 G.f. = 1 + x + 2*x^2 + 11*x^3 + 170*x^4 + 7429*x^5 + 920460*x^6 + 323801820*x^7 + ... - _Michael Somos_, May 15 2022 %p A051255 A051255 := proc(n) local i; mul((3*i+1)*(6*i)!*(2*i)!/((4*i)!*(4*i+1)!),i=0..n-1); end; %t A051255 a[n_] := Product[(3*i+1)*(6*i)!*(2*i)!/((4*i)!*(4*i+1)!), {i, 0, n-1}]; Table[a[n], {n, 0, 13}] (* _Jean-François Alcover_, Feb 25 2014 *) %o A051255 (PARI) a(n)=prod(i=0,n-1,(3*i+1)*(6*i)!*(2*i)!/((4*i)!*(4*i+1)!)); \\ _Joerg Arndt_, Feb 25 2014 %o A051255 (PARI) A051255(n)=prod(i=0,n-1,(3*i+1)*binomial(6*i,2*i)/binomial(4*i+1,2*i)/(2*i+1)) \\ _M. F. Hasler_, Oct 04 2018 %Y A051255 Cf. A006013, A049504. %K A051255 nonn,nice,easy %O A051255 0,3 %A A051255 _N. J. A. Sloane_ %E A051255 More terms from _Michel ten Voorde_ %E A051255 Missing a(0)=1 term added by _Michael Somos_, Feb 25 2014