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A135313 Triangle of numbers T(n,k) (n>=0, n>=k>=0) of transitive reflexive early confluent binary relations R on n labeled elements where k=max_{x}(|{y : xRy}|), read by rows. Early confluency means that (xRy AND xRz) implies (yRz OR zRy) for all x, y, z. +0
3
1, 0, 1, 0, 1, 3, 0, 1, 12, 13, 0, 1, 61, 106, 75, 0, 1, 310, 1105, 1035, 541, 0, 1, 1821, 12075, 16025, 11301, 4683, 0, 1, 11592, 141533, 267715, 239379, 137774, 47293, 0, 1, 80963, 1812216, 4798983, 5287506, 3794378, 1863044, 545835, 0, 1, 608832 (list; table; graph; listen)
OFFSET

0,6

COMMENT

Triangle begins : 1 0, 1 0, 1, 3 0, 1, 12, 13 0, 1, 61, 106, 75 0, 1, 310, 1105, 1035, 541 ... Diagonal is sequence A000670.

REFERENCES

A. P. Heinz (1990). Analyse der Grenzen und Moeglichkeiten schneller Tableauoptimierung. PhD Thesis, Albert-Ludwigs-Universitaet Freiburg, Freiburg i. Br., Germany.

LINKS

Alois P. Heinz (heinz(AT)hs-heilbronn.de), Dec 05 2007, Table of n, a(n) for n = 0..209

FORMULA

T(n,0)=A135302(n,0), T(n,k)=A135302(n,k)-A135302(n,k-1) for k>0; e.g.f. of column k=0: tt_0(x)=1, e.g.f. of column k>0: tt_k(x)=t_k(x)-t_{k-1}(x), where t_k(x)=exp(sum_{m=1..k}(x^m/m!*t_{k-m}(x))) if k>=0 and t_k(x)=0 else.

EXAMPLE

T(3,3)=13 because there are 13 relations of the given kind for 3 elements:

1R2, 2R1, 1R3, 3R1, 2R3, 3R2;

1R2, 1R3, 2R3, 3R2;

2R1, 2R3, 1R3, 3R1;

3R1, 3R2, 1R2, 2R1;

2R1, 3R1, 2R3, 3R2;

1R2, 3R2, 1R3, 3R1;

1R3, 2R3, 1R2, 2R1;

1R2, 2R3, 1R3;

1R3, 3R2, 1R2;

2R1, 1R3, 2R3;

2R3, 3R1, 2R1;

3R1, 1R2, 3R2;

3R2, 2R1, 3R1;

(the reflexive relationships 1R1, 2R2, 3R3 have been omitted for brevity)

MAPLE

t := proc(k) option remember; if k<0 then 0 else unapply(exp(sum('x^m/m!*t(k-m)(x)', 'm'=1..k)), x) fi; end; tt := proc(k) option remember; unapply((t(k)-t(k-1))(x), x); end; T := proc(n, k) option remember; coeff(series(tt(k)(x), x=0, n+1), x, n)*n!; end; seq(seq(T(n, k), k=0..n), n=0..12);

CROSSREFS

Cf. A135302, A000670.

Row sums are in A052880. [From Alois P. Heinz (heinz(AT)hs-heilbronn.de), Jun 01 2009]

Sequence in context: A112906 A137375 A145881 this_sequence A022695 A067169 A011339

Adjacent sequences: A135310 A135311 A135312 this_sequence A135314 A135315 A135316

KEYWORD

nonn,tabl

AUTHOR

Alois P. Heinz (heinz(AT)hs-heilbronn.de), Dec 05 2007

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Last modified December 8 08:31 EST 2009. Contains 170430 sequences.


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