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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. 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; refs; listen; history; internal format)
OFFSET

0,6

COMMENTS

Early confluency means that (xRy AND xRz) implies (yRz OR zRy) for all x, y, z.

REFERENCES

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

LINKS

Alois P. Heinz, Table of n, a(n) for n = 0..1034

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:  (1) 1R2, 2R1, 1R3, 3R1, 2R3, 3R2;  (2) 1R2, 1R3, 2R3, 3R2;  (3) 2R1, 2R3, 1R3, 3R1;  (4) 3R1, 3R2, 1R2, 2R1;  (5) 2R1, 3R1, 2R3, 3R2; (6) 1R2, 3R2, 1R3, 3R1;  (7) 1R3, 2R3, 1R2, 2R1;  (8) 1R2, 2R3, 1R3;  (9) 1R3, 3R2, 1R2;  (10) 2R1, 1R3, 2R3;  (11) 2R3, 3R1, 2R1;  (12) 3R1, 1R2, 3R2;  (13) 3R2, 2R1, 3R1; (the reflexive relationships 1R1, 2R2, 3R3 have been omitted for brevity).

Triangle begins:

1

0, 1

0, 1, 3

0, 1, 12, 13

0, 1, 61, 106, 75

0, 1, 310, 1105, 1035, 541

MAPLE

t:= proc(k) option remember; `if` (k<0, 0, unapply (exp (add (x^m/m! *t(k-m)(x), m=1..k)), x)) 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, n+1), x, n) *n! end: seq (seq (T(n, k), k=0..n), n=0..12);

CROSSREFS

Cf. A135302.

Diagonal gives: A000670.

Row sums are in A052880.

Sequence in context: A112906 A137375 A145881 * A022695 A197858 A060861

Adjacent sequences:  A135310 A135311 A135312 * A135314 A135315 A135316

KEYWORD

nonn,tabl

AUTHOR

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

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Last modified February 14 23:16 EST 2012. Contains 205687 sequences.