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!)
A057420 Axially symmetric n-celled polyominoes with 1 hole. 0
1, 3, 8, 25, 45, 137, 221, 650, 1006, 2857, 4370, 12050, 18417, 49516, 76037, 200184, 309411, 800440, 1245934, 3176482 (list; graph; refs; listen; history; text; internal format)
OFFSET

9,2

LINKS

Table of n, a(n) for n=9..28.

Tomás Oliveira e Silva, Enumeration of polyominoes

CROSSREFS

Sequence in context: A328272 A220486 A180380 * A076049 A026970 A026980

Adjacent sequences:  A057417 A057418 A057419 * A057421 A057422 A057423

KEYWORD

nonn

AUTHOR

N. J. A. Sloane, Sep 05 2000

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 April 17 05:36 EDT 2021. Contains 343059 sequences. (Running on oeis4.)