The On-Line Encyclopedia of Integer Sequences (OEIS)

Revision History for A234008

(Bold, blue-underlined text is an addition; faded, red-underlined text is a ~~deletion~~.)
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A234008

Free polyominoes with 2n squares, having 180-degree rotational symmetry about a square mid-side, but no reflective symmetry.
(history; published version)

#26 by Michel Marcus at Sat Apr 15 05:08:33 EDT 2023

STATUS

reviewed

approved

#25 by Joerg Arndt at Sat Apr 15 04:31:21 EDT 2023

STATUS

proposed

reviewed

#24 by John Mason at Sat Apr 15 04:23:46 EDT 2023

STATUS

editing

proposed

#23 by John Mason at Sat Apr 15 04:23:09 EDT 2023

DATA

0, 1, 4, 16, 60, 231, 877, 3362, 12905, 49825, 193003, 750581, 2927792, 11453171, 44911853, 176499605, 694954416, 2741031257, 10827727980, 42831355495, 169640762209, 672657218163, 2669990735153, 10608176066076, 42184579054003

KEYWORD

nonn,hard,more

EXTENSIONS

a(19)-a(25) from John Mason, Apr 15 2023

STATUS

approved

editing

Discussion

Sat Apr 15

04:23

John Mason: Added terms. Removed "more"

#22 by Joerg Arndt at Thu Dec 16 01:31:51 EST 2021

STATUS

reviewed

approved

#21 by Andrew Howroyd at Wed Dec 15 22:36:45 EST 2021

STATUS

proposed

reviewed

#20 by Jon E. Schoenfield at Mon Dec 13 18:53:32 EST 2021

STATUS

editing

proposed

#19 by Jon E. Schoenfield at Mon Dec 13 18:53:24 EST 2021

NAME

Free polyominoes with 2n squares, having 180 -degree rotational symmetry about a square mid-side, but no reflective symmetry.

STATUS

proposed

editing

#18 by John Mason at Mon Dec 13 09:30:31 EST 2021

STATUS

editing

proposed

#17 by John Mason at Mon Dec 13 09:27:49 EST 2021

DATA

0, 1, 4, 16, 60, 231, 877, 3362, 12905, 49825, 193003, 750581, 2927792, 11453171, 44911853, 176499605, 694954416, 2741031257

EXTENSIONS

a(12)-a(18) from John Mason, Dec 13 2021

Discussion

Mon Dec 13

09:30

John Mason: I added some terms.
I simplified the description and comment which I realise with hindsight contained superfluous detail.
Added a comment.