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

 

Logo

Thanks to everyone who made a donation during our annual appeal!
To see the list of donors, or make a donation, see the OEIS Foundation home page.

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A057425 Number of rotationally symmetric 2n-celled polyominoes with 1 hole. 0
1, 7, 42, 193, 853, 3553, 14564, 58636, 234523 (list; graph; refs; listen; history; text; internal format)
OFFSET

5,2

LINKS

Table of n, a(n) for n=5..13.

Tomás Oliveira e Silva, Enumeration of polyominoes

CROSSREFS

Sequence in context: A110451 A212144 A266387 * A248329 A073376 A094429

Adjacent sequences:  A057422 A057423 A057424 * A057426 A057427 A057428

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 January 23 19:45 EST 2020. Contains 331175 sequences. (Running on oeis4.)