A130622 - OEIS

%I #17 Jan 16 2023 15:42:25

%S 0,1,2,5,11,36,122,538,2526,13166,71153,400109,2300430,13504780,

%T 80547558,487327904

%N Number of polyominoes with perimeter at most 2n.

%C The perimeter of a polyomino is always even.

%C a(n) is partial sums of A057730.

%C a(n+1) >= A130866(n).

%C Is there another prime term beyond {2, 5, 11}?

%Y Cf. A131482 (number of n-celled polyominoes with perimeter 2n+2).

%Y Cf. A057730 (number of polyominoes (A000105) with perimeter 2n).

%Y Cf. A130866 (number of polyominoes with at most n cells).

%K hard,more,nonn

%O 1,3

%A _Tanya Khovanova_, Aug 10 2007

%E Offset corrected by _John Mason_, Jan 16 2023

%E a(9)-a(16) from _John Mason_, Jan 16 2023