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A059057 Penrice Christmas gift numbers, Card-matching numbers (Dinner-Diner matching numbers). 0
1, 0, 0, 2, 4, 0, 16, 0, 4, 80, 192, 216, 128, 96, 0, 8, 4752, 10752, 11776, 7680, 3936, 1024, 384, 0, 16, 440192, 975360, 1035680, 696320, 329600, 114176, 31040, 5120, 1280, 0, 32, 59245120, 129054720, 135477504, 90798080 (list; graph; refs; listen; history; text; internal format)



This is a triangle of card matching numbers. Two decks each have n kinds of cards, 2 of each kind. The first deck is laid out in order. The second deck is shuffled and laid out next to the first. A match occurs if a card from the second deck is next to a card of the same kind from the first deck. 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)!.

Rows are of length 1,3,5,7,...


F. N. David and D. E. Barton, Combinatorial Chance, Hafner, NY, 1962, Ch. 7 and Ch. 12.

J. Riordan, An Introduction to Combinatorial Analysis, Wiley, 1958, pp. 174-178.

R. P. Stanley, Enumerative Combinatorics Volume I, Cambridge University Press, 1997, p. 71.


Table of n, a(n) for n=0..39.

F. F. Knudsen and I. Skau, On the Asymptotic Solution of a Card-Matching Problem, Mathematics Magazine 69 (1996), 190-197.

Barbara H. Margolius, Dinner-Diner Matching Probabilities

B. H. Margolius, The Dinner-Diner Matching Problem, Mathematics Magazine, 76 (2003), 107-118.

S. G. Penrice, Derangements, permanents and Christmas presents, The American Mathematical Monthly 98(1991), 617-620.

Index entries for sequences related to card matching


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.


There are 16 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)=16.


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);

for n from 0 to 6 do seq(coeff(f(t, n, 2), t, m), m=0..2*n); od;


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[ Coefficient[r[x, n, k], x, j]*(t-1)^j*(n*k-j)!, {j, 0, n*k}]; Flatten[ Table[ Coefficient[ f[t, n, 2], t, m], {n, 0, 6}, {m, 0, 2 n}]](* Jean-Fran├žois Alcover, Nov 28 2011, translated from Maple *)


Cf. A008290, A059056-A059071.

Sequence in context: A078022 A203850 A106603 * A196225 A127511 A321956

Adjacent sequences:  A059054 A059055 A059056 * A059058 A059059 A059060




Barbara Haas Margolius (margolius(AT)math.csuohio.edu)



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Last modified March 1 03:32 EST 2021. Contains 341732 sequences. (Running on oeis4.)