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A367439 a(n) is the degree of the polyomino with binary code A246521(n+1) in the polyomino graph PG(n) defined in A367435.

%I A367439 #11 Dec 07 2023 14:53:45
%S A367439 0,0,1,1,4,3,4,3,2,10,8,3,9,10,9,8,9,10,8,4,2,15,28,15,12,12,10,17,14,
%T A367439 19,20,15,14,15,13,18,20,9,14,13,17,4,12,16,18,11,9,10,15,22,19,10,19,
%U A367439 14,16,3,36,36,35,31,28,30,36,22,29,37,16,11,28,13,24
%N A367439 a(n) is the degree of the polyomino with binary code A246521(n+1) in the polyomino graph PG(n) defined in A367435.
%C A367439 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), where the intermediate (the set of cells remaining when the cell to be moved is detached) is required to be a (connected) polyomino.
%C A367439 Can be read as an irregular triangle, whose m-th row contains A000105(m) terms, m >= 1.
%H A367439 Pontus von Brömssen, <a href="/A367439/b367439.txt">Table of n, a(n) for n = 1..6473</a> (rows 1..10).
%H A367439 <a href="/index/Pol#polyominoes">Index entries for sequences related to polyominoes</a>.
%F A367439 a(n) <= A367126(n).
%e A367439 As an irregular triangle:
%e A367439    0;
%e A367439    0;
%e A367439    1, 1;
%e A367439    4, 3, 4, 3,  2;
%e A367439   10, 8, 3, 9, 10, 9, 8, 9, 10, 8, 4, 2;
%e A367439   ...
%e A367439 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.
%Y A367439 Cf. A000105, A246521, A367126, A367435, A367437 (row maxima), A367438, A367443.
%K A367439 nonn,tabf
%O A367439 1,5
%A A367439 _Pontus von Brömssen_, Nov 18 2023