|
Search: id:A053022
|
|
|
| A053022 |
|
Number of sub-diagonal directed diagonally-convex animals with given diagonal semi-perimeter. |
|
+0
1
|
|
| 1, 1, 3, 9, 30, 107, 396, 1506, 5848, 23087, 92381, 373830, 1527192, 6290054, 26090780, 108895558, 456992576, 1927176941, 8162557837, 34708427777, 148110582311, 634074235584, 2722547715302, 11721572763762, 50591504811439
(list; graph; listen)
|
|
|
OFFSET
|
2,3
|
|
|
REFERENCES
|
F. Ibn-Majdoub-Hassani, Generating functions for directed animals convex following their direction, In: Actes du Seminaire Lotharingien de Combinatoire, 33rd session. Publication de l'IRMA, Strasbourg, France, 1994.
F. Ibn-Majdoub-Hassani, Combinatorics of polyominoes and oscillating shifted tableaux. Phd Thesis. Laboratoire de Recherche en Informatique, Univ. Paris-Sud, France, 1996
|
|
LINKS
|
Seminaire Lotharingien de Combinatoire, Home page
|
|
FORMULA
|
G.f.: A(x)^4 + 2x(1 - x + x^2)A(x)^3 + x( - 1 + 3x - 7x^2 + 5x^3 - 2x^4 + x^5)A(x)^2 + x^3(2 - 5x + 6x^2 - 3x^3 + 2x^4)A(x) + x^5( - 1 + 2x - x^2 + x^3) = 0
|
|
CROSSREFS
|
Sequence in context: A029651 A024332 A036727 this_sequence A128725 A099783 A032125
Adjacent sequences: A053019 A053020 A053021 this_sequence A053023 A053024 A053025
|
|
KEYWORD
|
nonn
|
|
AUTHOR
|
Fouad IBN MAJDOUB HASSANI (Fouad.Hassani(AT)genset.fr), Feb 24 2000
|
|
EXTENSIONS
|
More terms from Vladeta Jovovic (vladeta(AT)Eunet.yu), Mar 27 2001
|
|
|
Search completed in 0.002 seconds
|
