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 A003513 Number of regular sequences of length n. (Formerly M1685) 6
 1, 2, 6, 27, 192, 2280, 47097, 1735803, 115867758 (list; graph; refs; listen; history; text; internal format)
 OFFSET 2,2 REFERENCES N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence). LINKS Marc Davio, Unpublished notes, 1975, from a letter to N. J. A. Sloane sent in May 1975. Peter C. Fishburn, Fred S. Roberts, 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) 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] P. C. Fishburn et al., Van Lier Sequences, Discrete Appl. Math. 27 (1990), pp. 209-220. MAPLE A003513 := proc() local a, b, n ; a := {[1, 1]} ; n := 3 ; while true do b := {} ; for s in a do subsa := combinat[choose](s) ; for i in subsa do newa := add(k, k=i) ; if newa >= op(-1, s) then b := b union {[op(s), newa]} ; fi ; od; od; print(n, nops(b) ) ; a := b ; n := n+1 ; od; end: A003513() ; # R. J. Mathar, Oct 22 2007 CROSSREFS Sequences in the Fishburn-Roberts (1989) article: A005269, A005268, A234595, A005272, A003513, A008926. Sequence in context: A118085 A058712 A011834 * A113731 A113676 A183323 Adjacent sequences:  A003510 A003511 A003512 * A003514 A003515 A003516 KEYWORD nonn,nice,more AUTHOR EXTENSIONS a(9) from R. J. Mathar, Oct 22 2007 a(10) from Sean A. Irvine, Jun 15 2015 STATUS approved

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Last modified January 28 22:35 EST 2020. Contains 331328 sequences. (Running on oeis4.)