

A005500


Triangulations of the disk R_{n,1}.
(Formerly M1516)


19



1, 2, 5, 18, 88, 489, 3071, 20667, 146381, 1072760, 8071728, 61990477, 484182622
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OFFSET

0,2


COMMENTS

A row or column of the array in A169808.
Graphs can be enumerated and counted using the tool "plantri", in particular the command "./plantri s P4 c2m2 [n]".  Manfred Scheucher, Mar 08 2018


REFERENCES

C. F. Earl and L. J. March, Architectural applications of graph theory, pp. 327355 of R. J. Wilson and L. W. Beineke, editors, Applications of Graph Theory. Academic Press, NY, 1979.
N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).


LINKS

Table of n, a(n) for n=0..12.
G. Brinkmann and B. McKay, Plantri (program for generation of certain types of planar graph)
C. F. Earl and L. J. March, Architectural applications of graph theory, pp. 327355 of R. J. Wilson and L. W. Beineke, editors, Applications of Graph Theory. Academic Press, NY, 1979. (Annotated scanned copy)
C. F. Earl & N. J. A. Sloane, Correspondence, 19801981


FORMULA

a(n) = (A005505(n) + A002710(n))/2.  Max Alekseyev, Oct 29 2012


CROSSREFS

Cf. A002710, A005505, A169808.
Sequence in context: A142153 A287227 A094294 * A020025 A113715 A227094
Adjacent sequences: A005497 A005498 A005499 * A005501 A005502 A005503


KEYWORD

nonn,more


AUTHOR

N. J. A. Sloane


EXTENSIONS

Edited by Max Alekseyev, Oct 29 2012
a(7)a(12) from Manfred Scheucher, Mar 08 2018


STATUS

approved



