A005268 Number of elementary sequences of length n.

1, 1, 2, 4, 10, 31, 120, 578, 3422, 24504, 208833, 2086777, 24123293, 318800755, 4766262421, 79874304340, 1488227986802

Offset: 1

Author

N. J. A. Sloane

Keywords

• nonn
• more

Comments

In Fishburn-Roberts (1989) it is stated that no recurrence is known. - N. J. A. Sloane, Jan 04 2014

References

• Fishburn, Peter C.; Roberts, Fred S., Uniqueness in finite measurement. Applications of combinatorics and graph theory to the biological and social sciences, 103--137, IMA Vol. Math. Appl., 17, Springer, New York, 1989. MR1009374 (90e:92099)
• N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).

Links

• Fishburn, Peter C.; Roberts, Fred S., Uniqueness in finite measurement, in Applications of combinatorics and graph theory to the biological and social sciences, 103--137, IMA Vol. Math. Appl., 17, Springer, New York, 1989. MR1009374 (90e:92099). [Annotated scan of five pages only]
• Peter C. Fishburn, Fred S. Roberts, Elementary sequences, sub-Fibonacci sequences. Discrete Appl. Math. 44 (1993), no. 1-3, 261-281.
• Sean A. Irvine, Complete set of sequences for a(11)

Crossrefs

Sequences in the Fishburn-Roberts (1989) article: A005269, A005268, A234595, A005272, A003513, A008926.

Extensions

a(11) corrected and a(12)-a(14) from Sean A. Irvine, Apr 27 2016

a(15)-a(17) from Bert Dobbelaere, Dec 28 2020