A056398 Number of step shifted (decimated) sequence structures using exactly four different symbols.

0, 0, 0, 1, 3, 37, 63, 479, 1316, 8597, 14619, 155999, 211231, 1732907, 5302823, 21559909, 43398413, 466495335, 625545865, 5659500031, 15126813765, 72778025365, 132561145173, 1460519554091, 2338565021382

Offset: 1

Author

Marks R. Nester

Keywords

• nonn

Comments

See A056371 for an explanation of step shifts. Permuting the symbols will not change the structure.

References

• M. R. Nester (1999). Mathematical investigations of some plant interaction designs. PhD Thesis. University of Queensland, Brisbane, Australia. [See A056391 for pdf file of Chap. 2]

Crossrefs

Column 4 of A288620.

Cf. A056378.

Formula

A056393(n)-A056392(n).