A221961 Number of n X n symmetric lonesum ternary matrices.

1, 3, 18, 149, 1390, 13377

Offset: 0

Author

N. J. A. Sloane, Feb 05 2013

Keywords

• nonn
• more

Links

• H. K. Kim, D. S. Krotov and J. Y. Lee, Matrices uniquely determined by their lonesums, Linear Algebra and its Applications, 438 (2013) no 7, 3107-3123

Crossrefs

Cf. A000629 (the binary case).

See also A299906, A299907 for the general binary case.

Formula

Kim et al. (2013) give a formula.