cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A005272 Number of Van Lier sequences of length n.

Original entry on oeis.org

1, 2, 6, 26, 164, 1529, 21439, 461481, 15616226, 851607867, 76555549499, 11550559504086
Offset: 2

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From Fishburn et al.'s abstract (from the 1990 article): "We study two types of sequences of positive integers which arise from problems in the measurement of comparative judgements of probability. The first type consists of the Van Lier sequences, which are nondecreasing sequences x_1, x_2, ..., x_n of positive integers that start with two 1's and have the property that, whenever j < k <= n, x_k - x_j can be expressed as a sum of terms from the sequence other than x_j. The second type consists of the regular sequences, which are nondecreasing sequences of positive integers that start with two 1's and have the property that each subsequent term is a partial sum of preceding terms. ... We also study one-term extensions of Van Lier sequences and obtain some asymptotic results on the number of Van Lier sequences." - Jonathan Vos Post, Apr 16 2011

References

  • N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).

Crossrefs

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

Extensions

a(9)-a(10) from Sean A. Irvine, Apr 29 2016
a(11)-a(13) from Bert Dobbelaere, Jan 08 2020