%I #7 Apr 12 2023 10:51:52
%S 1,4,20,113,682,4294,27830,184240,1239575,8446660,58150684,403735761
%N a(n) is the number of n-celled fixed rounded polyominoes.
%C See A056840 for the definition of rounded polyominoes.
%Y Cf. A056840, A362224.
%K nonn,more
%O 1,2
%A _John Mason_, Apr 11 2023