A367126 - OEIS

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A367126

a(n) is the degree of the polyomino with binary code A246521(n+1) in the n-omino graph defined in A098891.

0, 0, 1, 1, 4, 3, 4, 3, 2, 10, 9, 5, 9, 10, 9, 8, 9, 10, 9, 4, 2, 16, 28, 16, 14, 12, 12, 18, 15, 20, 21, 16, 16, 16, 15, 18, 20, 11, 14, 13, 18, 6, 12, 16, 18, 11, 9, 11, 15, 22, 20, 11, 19, 14, 16, 3, 38, 36, 35, 33, 31, 32, 38, 25, 31, 38, 17, 14, 30, 14, 26

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,5

COMMENTS

Number of free polyominoes that can be made from the polyomino with binary code A246521(n+1) by moving one of its cells (not counting itself).

Can be read as an irregular triangle, whose m-th row contains A000105(m) terms, m >= 1.

LINKS

Pontus von Brömssen, Table of n, a(n) for n = 1..6473 (rows 1..10).

Index entries for sequences related to polyominoes.

FORMULA

a(n) >= A367439(n).

EXAMPLE

As an irregular triangle:

1, 1;

4, 3, 4, 3, 2;

10, 9, 5, 9, 10, 9, 8, 9, 10, 9, 4, 2;

...

For n = 8, A246521(8+1) = 30 is the binary code of the S-tetromino. By moving one cell of the S-tetromino, we can obtain the L, O, and T tetrominoes (but not the I tetromino), so a(8) = 3.

CROSSREFS

Cf. A000105, A098891, A246521, A367123, A367124 (row maxima), A367125, A367439, A367443.

Sequence in context: A367914 A238234 A367439 * A136627 A108171 A231475

Adjacent sequences: A367123 A367124 A367125 * A367127 A367128 A367129

KEYWORD

nonn,tabf

AUTHOR

Pontus von Brömssen, Nov 05 2023

STATUS

approved