Search: id:A005130 Results 1-1 of 1 results found. %I A005130 M1808 %S A005130 1,1,2,7,42,429,7436,218348,10850216,911835460,129534272700,31095744852375, %T A005130 12611311859677500,8639383518297652500,9995541355448167482000,19529076234661277104897200, %U A005130 64427185703425689356896743840,358869201916137601447486156417296 %N A005130 Robbins numbers: a(n) = Product_{k=0..n-1} (3k+1)!/(n+k)!; also the number of descending plane partitions whose parts do not exceed n; also the number of n X n alternating sign matrices (ASM's). %C A005130 An alternating sign matrix is a matrix of 0's, 1's and -1's such that (a) the sum of each row and column is 1; (b) the nonzero entries in each row and column alternate in sign. %C A005130 Contribution from Gary W. Adamson (qntmpkt(AT)yahoo.com), May 27 2009: (Start) %C A005130 Starting with offset 1 = row sums of triangle A160708, and convolution square of A160707. %C A005130 a(n) is odd iff n is a Jacobsthal number [Frey and Sellers, 2000]. %C A005130 Starting with offset 1 = row sums of triangle A160708. %C A005130 Starting (1, 2, 7,...) = convolution square of A160707: [1, 1, 3, 18, 192,...]. (End) %D A005130 G. E. Andrews, Plane partitions (III): the Weak Macdonald Conjecture, Invent. Math., 53 (1979), 193-225. (See Theorem 10.) %D A005130 D. M. Bressoud, Proofs and Confirmations, Camb. Univ. Press, 1999; A_n on page 4, D_r on page 197. %D A005130 D. M. Bressoud and J. Propp, How the alternating sign matrix conjecture was solved, Notices Amer. Math. Soc., 46 (No. 6, 1999), 637-646. %D A005130 M. Ciucu, The equivalence between enumerating cyclically symmetric, self-complementary and totally symmetric, self-complementary plane partitions, J. Combin. Theory Ser. A 86 (1999), 382-389. %D A005130 C. A. Pickover, Wonders of Numbers, "Princeton Numbers", Chapter 83, Oxford Univ. Press NY 2001. %D A005130 D. P. Robbins, The story of 1, 2, 7, 42, 429, 7436, ..., Math. Intellig., 13 (No. 2, 1991), 12-19. %D A005130 N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence). %D A005130 R. P. Stanley, A baker's dozen of conjectures concerning plane partitions, pp. 285-293 of "Combinatoire Enumerative (Montreal 1985)", Lect. Notes Math. 1234, 1986. %D A005130 D. Zeilberger, A constant term identity featuring the ubiquitous (and mysterious) Andrews-Mills-Robbins-Rumsey numbers 1, 2, 7, 42, 429, ..., J. Combin. Theory, A 66 (1994), 17-27. %D A005130 D. Zeilberger, Dave Robbins's Art of Guessing, Adv. in Appl. Math. 34 (2005), 939-954. %H A005130 T. D. Noe, Table of n, a(n) for n = 0..100 %H A005130 M. T. Batchelor, J. de Gier and B. Nienhuis, The quantum symmetric XXZ chain at Delta=-1/ 2, alternating sign matrices and plane partitions, arXiv cond-mat/ 0101385 %H A005130 F. Colomo and A. G. Pronko, On the refined 3-enumeration of alternating sign matrices, Advances in Applied Mathematics 34 (2005) 798. %H A005130 F. Colomo and A. G. Pronko, Square ice, alternating sign matrices and classical orthogonal polynomials, JSTAT (2005) P01005. %H A005130 I. Fischer, The number of monotone triangles with prescribed bottom row %H A005130 P. Di Francesco, A refined Razumov-Stroganov conjecture II %H A005130 P. Di Francesco, P. Zinn-Justin and J.-B. Zuber, Determinant formulae for some tiling problems... %H A005130 D. D. Frey and J. A. Sellers, Journal of Integer Sequences Vol. 3 (2000) #00.2.3, Jacobsthal Numbers and Alternating Sign Matrices %H A005130 D. D. Frey and J. A. Sellers, Prime Power Divisors of the Number of n X n Alternating Sign Matrices %H A005130 J. de Gier, Loops, matchings and alternating-sign matrices %H A005130 G. Kuperberg, Another proof of the alternating-sign matrix conjecture, Internat. Math. Res. Notices, No. 3, (1996), 139-150. %H A005130 G. Kuperberg, Symmetry classes of alternating-sign matrices under one roof, arXiv math.CO/ 0008184 %H A005130 J. Propp, The many faces of alternating-sign matrices. %H A005130 A. V. Razumov and Yu. G. Stroganov, Spin chains and combinatorics, arXiv cond-mat/0012141 %H A005130 D. P. Robbins, Symmetry classes of alternating sign matrices, arXiv:math.CO/0008045 %H A005130 Yu. G. Stroganov, 3-enumerated alternating sign matrices %H A005130 Eric Weisstein's World of Mathematics, Link to a section of The World of Mathematics (1). %H A005130 Eric Weisstein's World of Mathematics, Link to a section of The World of Mathematics (2). %H A005130 D. Zeilberger, Proof of the alternating-sign matrix conjecture, arXiv:math.CO/9407211 %H A005130 D. Zeilberger, Proof of the alternating-sign matrix conjecture, Elec. J. Combin., Vol. 3 (Number 2) (1996), #R13. %H A005130 D. Zeilberger, [math/9606224] Proof of the Refined Alternating Sign Matrix Conjecture %H A005130 D. Zeilberger, A constant term identity featuring the ubiquitous(and mysterious)Andrews-Mills-Robbins-Ramsey numbers 1,2,7,42,429,... %H A005130 D. Zeilberger, Dave Robbins's Art of Guessing, Adv. in Appl. Math. 34 (2005), 939-954. %H A005130 Index entries for sequences related to factorial numbers %H A005130 Index entries for "core" sequences %F A005130 a(n) = Product_{k=0..n-1} (3k+1)!/(n+k)!. %F A005130 The Hankel transform of A025748 is a(n)3^binomial(n,2). %F A005130 a(n) = sqrt(A049503). %p A005130 A005130 := proc(n) local k; mul((3*k+1)!/(n+k)!,k=0..n-1); end; %t A005130 f[n_] := Product[(3k + 1)!/(n + k)!, {k, 0, n - 1}]; Table[ f[n], {n, 0, 17}] (from Robert G. Wilson v Jul 15 2004) %o A005130 (PARI) a(n)=if(n<0,0,prod(k=0,n-1,(3*k+1)!/(n+k)!)) %o A005130 (PARI) a(n)=local(A); if(n<0,0,A=Vec((1-(1-9*x+O(x^(2*n)))^(1/3))/(3*x)); matdet(matrix(n,n,i,j,A[i+j-1]))/3^binomial(n,2)) %Y A005130 Cf. A006366, A048601, also A003827, A005156, A005158, A005160-A005164, A050204, A049503. %Y A005130 Cf. A160707, A160708. %Y A005130 Sequence in context: A066383 A011802 A007065 this_sequence A091669 A108042 A152559 %Y A005130 Adjacent sequences: A005127 A005128 A005129 this_sequence A005131 A005132 A005133 %K A005130 nonn,easy,nice,core %O A005130 0,3 %A A005130 N. J. A. Sloane (njas(AT)research.att.com). Search completed in 0.002 seconds