login
The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A051738 Number of rooted 2-dimensional polyominoes with n pentagonal cells, with no symmetries removed. 3
1, 5, 30, 180, 1075, 6366, 37520, 220500, 1293615, 7581240, 44398387, 259881960, 1520633270, 8895116230 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

Number of polypents (like polyominoes, with pentagons) with n cells. These are anchored polypents, with no culling for reflection or rotation (or translation) isomorphism.

REFERENCES

Dan Hoey, Bill Gosper and Richard C. Schroeppel, Discussions in Math-Fun Mailing list, circa Jul 13 1999.

LINKS

Table of n, a(n) for n=1..14.

R. C. Schroeppel, A few mathematical experiments

CROSSREFS

A row of A094166.

Sequence in context: A105481 A242157 A094167 * A052934 A136785 A227383

Adjacent sequences:  A051735 A051736 A051737 * A051739 A051740 A051741

KEYWORD

nonn

AUTHOR

Richard C. Schroeppel, Feb 13 2002

EXTENSIONS

More terms from N. J. A. Sloane, May 06 2004

Edited by N. J. A. Sloane, Sep 15 2008 at the suggestion of R. J. Mathar

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified February 22 23:44 EST 2020. Contains 332157 sequences. (Running on oeis4.)