A308300 T(n,k) is the number of simply connected square animals with n cells and k internal vertices (0 <= k <= A083479(n)), triangle read by rows.

1, 1, 2, 4, 1, 11, 1, 27, 7, 1, 82, 21, 4, 250, 90, 21, 2, 815, 334, 89, 9, 1, 2685, 1311, 391, 67, 6, 9072, 4978, 1674, 324, 45, 1, 30889, 19030, 7089, 1630, 275, 23, 1, 106290, 72082, 29433, 7629, 1498, 174, 11

Offset

1,3

Links

John Mason, Table of n, a(n) for n = 1..95, rows 1..18

Elena V. Konstantinova, The constructive enumeration of square animals, POSTECH 10 (2000).

Elena V. Konstantinova and Maxim V. Vidyuk, Discriminating tests of information and topological indices. Animals and trees, J. Chem. Inf. Comput. Sci. 43 (2003), 1860-1871, Table 2.

Example

The table starts:
       1;
       1;
       2;
       4,     1;
      11,     1;
      27,     7,     1;
      82,    21,     4;
     250,    90,    21,    2;
     815,   334,    89,    9,    1;
    2685,  1311,   391,   67,    6;
    9072,  4978,  1674,  324,   45,   1;
   30889, 19030,  7089, 1630,  275,  23,  1;
  106290, 72082, 29433, 7629, 1498, 174, 11;
  ...

Crossrefs

Cf. A000104 (row sums), A350030 (first column of this sequence).

Sequence in context: A355144 A346419 A048941 * A246188 A135333 A124503

Adjacent sequences: A308297 A308298 A308299 * A308301 A308302 A308303

Keyword

nonn,tabf

Author

R. J. Mathar, May 19 2019

Status

approved