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A000186 Number of 3 X n Latin rectangles in which the first row is in order.
(Formerly M2140 N0851)
20
1, 0, 0, 2, 24, 552, 21280, 1073760, 70299264, 5792853248, 587159944704, 71822743499520, 10435273503677440, 1776780700509416448, 350461958856515690496, 79284041282622163140608, 20392765404792755583221760, 5917934230798104348783083520, 1924427226324694427836833857536 (list; graph; refs; listen; history; internal format)
OFFSET

0,4

COMMENTS

Or number of nXn matrices with exactly one 1 and one 2 in each row and column which are not in the main diagonal, other entries 0. [From Vladimir Shevelev (shevelev(AT)bgu.ac.il), Mar 22 2010]

REFERENCES

K. P. Bogart and J. Q. Longyear, Counting 3 by n Latin rectangles, Proc. Amer. Math. Soc., 54 (1976), 463-467.

L. Comtet, Advanced Combinatorics, Reidel, 1974, p. 183.

I. Gessel, Counting three-line Latin rectangles, Lect. Notes Math, 1234(1986), 106-111. [From Vladimir Shevelev (shevelev(AT)bgu.ac.il), Mar 25 2010]

Goulden and Jackson, Combin. Enum., Wiley, 1983 p. 284.

S. M. Jacob, The enumeration of the Latin rectangle of depth three..., Proc. London Math. Soc., 31 (1928), 329-336.

S. M. Kerawala, The enumeration of the Latin rectangle of depth three by means of a difference equation, Bull. Calcutta Math. Soc., 33 (1941), 119-127.

S. M. Kerawala, The asymptotic number of three-deep Latin rectangles, Bull. Calcutta Math. Soc., 39 (1947), 71-72.

Koichi, Yamamoto, An asymptotic series for the number of three-line Latin rectangles, J. Math. Soc. Japan 1, (1950). 226-241.

W. Moser. A generalization of Riordan's formula for 3Xn Latin rectangles, Discrete Math., 40, 311-313 [From Vladimir Shevelev (shevelev(AT)bgu.ac.il), Mar 25 2010]

J. Riordan, An Introduction to Combinatorial Analysis, Wiley, 1958, p. 210.

V. S. Shevelev, Reduced Latin rectangles and square matrices with indentical sums in the rows and columns [Russian], Diskret. Mat., 4 (1992), no. 1, 91-110.

V. S. Shevelev, A generalized Riordan formula for three-rowed Latin rectangles and its applications, DAN of the Ukraine, 2 (1991), 8-12 (in Russian) [From Vladimir Shevelev (shevelev(AT)bgu.ac.il), Mar 25 2010]

Vladimir Shevelev, SPECTRUM OF PERMANENTS VALUES AND ITS EXTREMAL MAGNITUDES ..., Arxiv preprint arXiv:1104.4051, 2011.

N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 (includes this sequence).

N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).

D. S. Stones, The many formulae for the number of Latin rectangles, Electron. J. Combin 17 (2010), A1.

D. S. Stones and I. M. Wanless, Divisors of the number of Latin rectangles, J. Combin. Theory Ser. A 117 (2010), 204-215.

LINKS

N. J. A. Sloane, Table of n, a(n) for n = 0..207

Index entries for sequences related to Latin squares and rectangles

FORMULA

a(n)=n!*Sum_{k+j<=n} (2^j/j!)*k!*binomial(-3*(k+1), n-k-j).

Note that the formula Sum_{k=0..n, k <= n/2} binomial(n, k)D(n-k)*D(k)*U(n-2*k), where D() = A000166, U() = A000179 given by Riordan, p. 209 gives the wrong answers unless we set U(1) = -1 (or in other words we must take U() = A102761). With U(1) = 0 it produces A170904. See the Maple code here. - N. J. A. Sloane, Jan 21 2010, Apr 04 2010. Thanks to Vladimir Shevelev for clarifying this comment.

MAPLE

for n from 1 to 250 do t0:=0; for j from 0 to n do for k from 0 to n-j do t0:=t0 + (2^j/j!)*k!*binomial(-3*(k+1), n-k-j); od: od: t0:=n!*t0; lprint(n, t0); od:

Maple code for A000186 based on Eq. (30) of Riordan, p. 205. Eq. (30a) on p. 206 is wrong. - N. J. A. Sloane, Jan 21 2010. Thanks to Neven Juric for correcting an error in the definition of fU, Mar 01 2010

# A000166

unprotect(D);

D := proc(n) option remember; if n<=1 then 1-n else (n-1)*(D(n-1)+D(n-2)); fi; end;

[seq(D(n), n=0..30)];

# A000179

U := proc(n) if n<=1 then 1-n else

add ((-1)^k*(2*n)*binomial(2*n-k, k)*(n-k)!/(2*n-k), k=0..n); fi; end;

[seq(U(n), n=0..30)];

# funny A000179

fU := proc(n) global U; if n<=-2 then U(-n) elif abs(n)=1 then -1 elif n=0 then 2 else U(n); fi; end;

[seq(fU(n), n=-10..10)];

# A000186

K:=proc(n) local k; global D, fU; (1/2)*add( binomial(n, k)*D(n-k)*D(k)*fU(n-2*k), k=0..n ); end;

[seq(K(n), n=0..30)];

MATHEMATICA

a[n_] := (t0 = 0; Do[t0 = t0 + (2^j/j!)*k!*Binomial[-3*(k+1), n-k-j], {j, 0, n}, {k, 0, n-j}]; n!*t0); Table[a[n], {n, 0, 18}] (* From Jean-François Alcover, Oct 13 2011, after Maple *)

CROSSREFS

Cf. A000512.

Sequence in context: A138450 A054946 A046744 * A012113 A156525 A170904

Adjacent sequences:  A000183 A000184 A000185 * A000187 A000188 A000189

KEYWORD

nonn,nice,easy

AUTHOR

N. J. A. Sloane (njas(AT)research.att.com).

EXTENSIONS

Formula and more terms from Vladeta Jovovic (vladeta(AT)eunet.rs), Mar 31 2001

Edited by N. J. A. Sloane, Jan 21 2010, Mar 04 2010, Apr 04 2010

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Last modified February 16 16:51 EST 2012. Contains 205938 sequences.