A052281 Number of 4 X 4 symmetric stochastic matrices under row and column permutations.

1, 1, 3, 6, 16, 29, 62, 107, 195, 320, 522, 804, 1234, 1804, 2626, 3700, 5155, 7038

Offset

0,3

Comments

This sequence appears to be an erroneous version of A333886.

Links

Table of n, a(n) for n=0..17.

Example

There are 6 nonisomorphic symmetric 4 X 4 matrices with row and column sums 3:
[0 0 0 3] [0 0 1 2] [0 0 1 2] [0 0 1 2] [0 0 1 2] [0 1 1 1]
[0 0 3 0] [0 0 2 1] [0 1 1 1] [0 1 2 0] [0 2 1 0] [1 0 1 1]
[0 3 0 0] [1 2 0 0] [1 1 1 0] [1 2 0 0] [1 1 0 1] [1 1 0 1]
[3 0 0 0] [2 1 0 0] [2 1 0 0] [2 0 0 1] [2 0 1 0] [1 1 1 0]
But, A333886 gives 6 other cases.

Crossrefs

Cf. A053493, A001496, A052280, A052282.

Sequence in context: A321409 A151954 A032247 * A295062 A291611 A308401

Adjacent sequences: A052278 A052279 A052280 * A052282 A052283 A052284

Keyword

more,nonn,unkn

Author

Vladeta Jovovic, Feb 06 2000

Status

approved