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.

A193176 A193175(n)/2.

Original entry on oeis.org

2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 24, 25, 27, 30, 33, 35, 42, 45
Offset: 1

Views

Author

N. J. A. Sloane, Jul 17 2011

Keywords

References

  • Mermin, N. David; Rokhsar, Daniel S.; and Wright, David C.; Beware of 46-fold symmetry: the classification of two-dimensional quasicrystallographic lattices. Phys. Rev. Lett. 58 (1987), 2099-2101.

Crossrefs

Cf. A193175.

A193179 Number of classes of two-dimensional generalized Bravais lattices with 2n-fold symmetry.

Original entry on oeis.org

1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 3, 1, 1, 3, 1, 2, 9, 1, 9, 17, 1, 32, 1, 3, 34, 19, 2, 5, 121, 1, 211, 55, 1, 201, 695, 32, 43
Offset: 2

Views

Author

N. J. A. Sloane, Jul 17 2011

Keywords

Comments

Related to class numbers of cyclotomic fields, although the precise relationship is not clear to me. Compare A000927.

References

  • Mermin, N. David; Rokhsar, Daniel S.; and Wright, David C.; Beware of 46-fold symmetry: the classification of two-dimensional quasicrystallographic lattices. Phys. Rev. Lett. 58 (1987), 2099-2101.

Crossrefs

See A193175 for values of 2n such that a(n) = 1.
Cf. A000927.
Showing 1-2 of 2 results.

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

Content is available under The OEIS End-User License Agreement.