A007017 Number of motifs in triangular window of side n. (Formerly M2935)

1, 3, 12, 65, 480, 4851, 67256, 1281258, 33576120, 1211321683, 60197760876, 4122762095127, 389255776509600, 50680509287223315, 9101288287232978112, 2254758094831392182844

Offset

0,2

Comments

Also, half the number of (n+1) X (n+1) X (n+1) triangular binary arrays with no upright or inverted 2 X 2 X 2 subtriangle that is all 0's or all 1's. - R. H. Hardin, Oct 22 2010

References

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

L. Vuillon (vuillon(AT)lmd.univ-mrs.fr), "Contribution a l'etude des pavages et des surfaces dicretisees", Dissertation, Universite de la mediterranee, Marseille, France 1996.

Links

R. H. Hardin, Table of n, a(n) for n = 0..19

G. Rauzy, Notes/Letter to N. J. A. Sloane, n.d.

Crossrefs

Sequence in context: A368265 A242575 A144297 * A183273 A082987 A086836

Adjacent sequences: A007014 A007015 A007016 * A007018 A007019 A007020

Keyword

nonn

Author

G. Rauzy

Extensions

More terms from I. Gambini and L. Vuillon (vuillon(AT)lmd.univ-mrs.fr)

Offset set to 0 to match comment and b-file - R. J. Mathar, Oct 22 2010

Status

approved