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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A038162 Numbers missing from A038161.

Original entry on oeis.org

4, 8, 11, 13, 17, 19, 22, 24, 26, 29, 30, 32, 34, 36, 38, 41, 43, 46, 48, 51, 53, 54, 55, 57, 59, 62, 65, 67, 69, 71, 74, 76, 78, 80, 81, 82, 84, 87, 88, 90, 92, 94, 96, 98, 100, 101, 103, 105, 107, 109, 111, 113, 116, 118, 119, 121, 123, 125, 127
Offset: 1

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Author

N. J. A. Sloane

Keywords

Links

Crossrefs

Cf. A035019, A038161, A038590.

A038590 Sizes of clusters in hexagonal lattice A_2 centered at lattice point.

Original entry on oeis.org

1, 7, 13, 19, 31, 37, 43, 55, 61, 73, 85, 91, 97, 109, 121, 127, 139, 151, 163, 169, 187, 199, 211, 223, 235, 241, 253, 265, 271, 283, 295, 301, 313, 337, 349, 361, 367, 379, 385, 397, 409, 421, 433, 439, 451, 463, 475, 499, 511, 517, 535, 547
Offset: 0

Views

Author

N. J. A. Sloane

Keywords

Comments

The hexagonal lattice is the familiar 2-dimensional lattice in which each point has 6 neighbors. This is sometimes called the triangular lattice.
The sequence can be approximated by a linear function with a correction term. See link for the function and representation of the deviation. The structures in the difference function can also be set to music after scaling. Some MIDI examples are linked. - Hugo Pfoertner, Mar 16 2024

References

  • J. H. Conway and N. J. A. Sloane, "Sphere Packings, Lattices and Groups", Springer-Verlag, p. 111.
  • B. K. Teo and N. J. A. Sloane, Atomic Arrangements and Electronic Requirements for Close-Packed Circular and Spherical Clusters, Inorganic Chemistry, 25 (1986), pp. 2315-2322. See Table IV.

Links

Crossrefs

Cf. A004016, A035019, A038161, A038589.

Formula

Unique(A038589). Or, partial sums of A035019.
Showing 1-2 of 2 results.

Started in 1964 by Neil J. A. Sloane | Maintained by The OEIS Foundation Inc.

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