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 A059056 #24 Sep 26 2017 05:08:10 %S A059056 1,0,0,1,1,0,4,0,1,10,24,27,16,12,0,1,297,672,736,480,246,64,24,0,1, %T A059056 13756,30480,32365,21760,10300,3568,970,160,40,0,1,925705,2016480, %U A059056 2116836,1418720,677655,243360,67920,14688,2655,320,60,0,1 %N A059056 Penrice Christmas gift numbers, Card-matching numbers (Dinner-Diner matching numbers): Triangle T(n,k) = number of ways to get k matches for a deck with n cards, 2 of each kind. %C A059056 This is a triangle of card matching numbers. A deck has n kinds of cards, 2 of each kind. The deck is shuffled and dealt in to n hands with 2 cards each. A match occurs for every card in the j-th hand of kind j. Triangle T(n,k) is the number of ways of achieving exactly k matches (k=0..2n). The probability of exactly k matches is T(n,k)/((2n)!/2^n). %C A059056 Rows are of length 1,3,5,7,... = A005408(n). [Edited by _M. F. Hasler_, Sep 21 2015] %C A059056 Analogous to A008290. - _Zerinvary Lajos_, Jun 10 2005 %D A059056 F. N. David and D. E. Barton, Combinatorial Chance, Hafner, NY, 1962, Ch. 7 and Ch. 12. %D A059056 J. Riordan, An Introduction to Combinatorial Analysis, Wiley, 1958, pp. 174-178. %D A059056 R. P. Stanley, Enumerative Combinatorics Volume I, Cambridge University Press, 1997, p. 71. %H A059056 F. F. Knudsen and I. Skau, <a href="http://www.jstor.org/stable/2691467">On the Asymptotic Solution of a Card-Matching Problem</a>, Mathematics Magazine 69 (1996), 190-197. %H A059056 Barbara H. Margolius, <a href="http://academic.csuohio.edu/bmargolius/homepage/dinner/dinner/cardentry.htm">Dinner-Diner Matching Probabilities</a> %H A059056 B. H. Margolius, <a href="http://www.jstor.org/stable/3219303">The Dinner-Diner Matching Problem</a>, Mathematics Magazine, 76 (2003), 107-118. %H A059056 S. G. Penrice, <a href="http://www.jstor.org/stable/2324927">Derangements, permanents and Christmas presents</a>, The American Mathematical Monthly 98(1991), 617-620. %H A059056 <a href="/index/Ca#cardmatch">Index entries for sequences related to card matching</a> %F A059056 G.f.: sum(coeff(R(x, n, k), x, j)*(t-1)^j*(n*k-j)!, j=0..n*k) where n is the number of kinds of cards, k is the number of cards of each kind (here k is 2) and R(x, n, k) is the rook polynomial given by R(x, n, k)=(k!^2*sum(x^j/((k-j)!^2*j!))^n (see Stanley or Riordan). coeff(R(x, n, k), x, j) indicates the j-th coefficient on x of the rook polynomial. %e A059056 There are 4 ways of matching exactly 2 cards when there are 2 different kinds of cards, 2 of each in each of the two decks so T(2,2)=4. %e A059056 Triangle begins: %e A059056 1 %e A059056 "0", 0, 1 %e A059056 1, '0', "4", 0, 1 %e A059056 10, 24, 27, '16', "12", 0, 1 %e A059056 297, 672, 736, 480, 246, '64', "24", 0, 1 %e A059056 13756, 30480, 32365, 21760, 10300, 3568, 970, '160', "40", 0, 1 %e A059056 925705, 2016480, 2116836, 1418720, 677655, 243360, 67920, 14688, 2655, '320', "60", 0, 1 %e A059056 Diagonal " ": T(n,2n-2) = 0, 4, 12, 24, 40, 60, 84, 112, 144, ... equals A046092 %e A059056 Diagonal ' ': T(n,2n-3) = 0, 16, 64, 160, 320, 560, 896, 1344, ... equals A102860 %p A059056 p := (x,k)->k!^2*sum(x^j/((k-j)!^2*j!),j=0..k); R := (x,n,k)->p(x,k)^n; f := (t,n,k)->sum(coeff(R(x,n,k),x,j)*(t-1)^j*(n*k-j)!,j=0..n*k); %p A059056 for n from 0 to 7 do seq(coeff(f(t,n,2),t,m)/2^n,m=0..2*n); od; %t A059056 p[x_, k_] := k!^2*Sum[ x^j/((k-j)!^2*j!), {j, 0, k}]; %t A059056 R[x_, n_, k_] := p[x, k]^n; %t A059056 f[t_, n_, k_] := Sum[ Coefficient[ R[x, n, k], x, j]*(t-1)^j*(n*k-j)!, {j, 0, n*k}]; %t A059056 Table[ Coefficient[ f[t, n, 2]/2^n, t, m], {n, 0, 6}, {m, 0, 2*n}] // Flatten %t A059056 (* _Jean-François Alcover_, Sep 17 2012, translated from Maple *) %Y A059056 Cf. A059056-A059071, A008290. %K A059056 nonn,tabf,nice %O A059056 0,7 %A A059056 Barbara Haas Margolius (margolius(AT)math.csuohio.edu) %E A059056 Additional comments from _Zerinvary Lajos_, Jun 18 2007 %E A059056 Edited by _M. F. Hasler_, Sep 21 2015