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.

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A332050 Number of ways to arrange Palago tiles in a triangle of side length n, up to rotation, reflection, and swapping colors.

Original entry on oeis.org

1, 1, 7, 129, 9882, 2391930, 1743402771, 3812799008214, 25015772571200361, 492385451093553791610, 29074868501520453489499806, 5150525730438768829942800034449, 2737200544710109691113626131721984885, 4363981784043856212945753449232929426200329
Offset: 0

Views

Author

Peter Kagey, Feb 06 2020

Keywords

Comments

A Palago tile is a hexagonal tile with four regions of alternating colors. See links for illustrations.

Crossrefs

Programs

  • Mathematica
    a[n_] = (3^Binomial[n + 1, 2] +
        3*3^((Binomial[n + 1, 2] - Ceiling[n/2])/2) +
        If[Mod[n, 3] == 1, 0, 2*3^(Binomial[n + 1, 2]/3)])/6

Formula

a(n) = (3^A000217(n) + 3*3^A002620(n) + 2*3^A007997(n+4))/6 if n = 1 (mod 3), and
a(n) = (3^A000217(n) + 3*3^A002620(n))/6 otherwise.
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