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.

Showing 1-2 of 2 results.

A322345 Maximal number of vertices of a convex lattice polygon containing n lattice points in its interior.

Original entry on oeis.org

4, 6, 6, 6, 8, 7, 8, 9, 8, 8, 10, 9, 9, 10, 10, 10, 10, 11, 10, 12, 12, 12, 11, 11, 12, 12, 12, 13, 12, 12, 13, 13, 13, 13, 14, 14, 13, 13, 14, 14, 14, 14, 14, 14, 14, 15, 14, 15, 15, 15, 15, 15, 16, 15, 16, 15, 16, 16, 15, 15, 16, 16, 16, 16, 16, 16, 16, 16, 17, 17, 16, 17, 17, 16, 17, 17
Offset: 0

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Author

Hugo Pfoertner, Dec 04 2018

Keywords

Comments

This is an inverse of A063984 in the following sense: A063984(k) = min {n : a(n)>=k}. Thus a(n) grows roughly like const*n^(1/3). - Günter Rote, Sep 19 2023

Crossrefs

Programs

  • Python
    # See the Python program in the links section.

Extensions

a(0) added by Andrey Zabolotskiy, Dec 29 2021
Name clarified by Günter Rote, Sep 18 2023
a(31) onwards from Günter Rote, Oct 01 2023

A298755 Quantitative (discrete) Helly numbers for the integer lattice Z^2.

Original entry on oeis.org

4, 6, 6, 6, 8, 7, 8, 9, 8, 8, 10, 9, 9, 10, 10, 10, 10, 11, 11, 12, 12, 12, 11, 11, 12, 12, 12, 13, 12, 12, 13, 13, 13, 13, 14, 14, 13, 13, 14, 14, 14, 14, 14, 14, 14, 15, 14, 15, 15, 15, 15, 15, 16, 15, 16, 15, 16, 16, 15, 15, 16, 16, 16, 16, 16, 16, 16, 16, 17, 17, 16, 17, 17, 17, 17, 17
Offset: 0

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Author

Keywords

Comments

a(n) = c(Z^2,n) is the smallest k>0 such that for every collection of convex sets C_1, ..., C_m having n points of Z^2 in common, there exists a subset of this collection of at most k elements such that they still contain exactly n points of Z^2 in common.
c(Z^2,n) = g(Z^2,n) = A298562(n) for n = 0, 1, ..., 200, but it is not known whether they agree for every n or not.

Crossrefs

Cf. A298562.

Formula

a(n) = max_{m=0..n} (A298562(m) + m - n). [Averkov et al.] - Andrey Zabolotskiy, Oct 02 2023

Extensions

a(31) onwards from Andrey Zabolotskiy, Oct 02 2023
Showing 1-2 of 2 results.