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 1-3 of 3 results.

A214665 The y-coordinates of prime numbers in an Ulam spiral oriented counterclockwise with first step east.

Original entry on oeis.org

0, 1, 1, -1, 0, 2, 2, 0, -2, 1, 3, 3, -1, -3, -3, 0, 4, 4, 2, -2, -4, -4, -3, 3, 5, 5, 3, -1, -3, -5, 0, 4, 6, 6, 2, 0, -6, -6, -6, -3, 3, 5, 7, 7, 7, 5, -7, -7, -6, -4, 0, 6, 8, 8, 8, 2, -4, -6, -8, -8, -8, -5, 9, 9, 9, 9, 3, -3, -9, -9, -9, -9, -4, 2, 8, 10
Offset: 1

Views

Author

William Rex Marshall, Jul 26 2012

Keywords

Comments

The eight possible orientations of the Ulam spiral can be derived from combining either A214664 or A214666 with either A214665 or A214667 as ordered pairs of coordinates.

Links

Crossrefs

Cf. A000040, A063826, A214664, A214666, A214667.

A214664 The x-coordinates of prime numbers in an Ulam spiral oriented counterclockwise with first step east.

Original entry on oeis.org

1, 1, -1, -1, 2, 2, -2, -2, 0, 3, 3, -3, -3, -3, 1, 4, 2, 0, -4, -4, -4, 2, 5, 5, -1, -5, -5, -5, -5, -3, 6, 6, 2, 0, -6, -6, -6, 0, 4, 7, 7, 7, -1, -3, -7, -7, -7, 5, 8, 8, 8, 8, 8, -2, -8, -8, -8, -8, -4, 0, 2, 9, 9, 5, 3, -1, -9, -9, -5, -3, 1, 7, 10, 10
Offset: 1

Views

Author

William Rex Marshall, Jul 26 2012

Keywords

Comments

The eight possible orientations of the Ulam spiral can be derived by combining either A214664 or A214666 with either A214665 or A214667 as ordered pairs of coordinates.

Links

Crossrefs

Cf. A000040, A063826, A214665, A214666, A214667.

A214666 The x-coordinates of prime numbers in an Ulam spiral oriented counterclockwise with first step west.

Original entry on oeis.org

-1, -1, 1, 1, -2, -2, 2, 2, 0, -3, -3, 3, 3, 3, -1, -4, -2, 0, 4, 4, 4, -2, -5, -5, 1, 5, 5, 5, 5, 3, -6, -6, -2, 0, 6, 6, 6, 0, -4, -7, -7, -7, 1, 3, 7, 7, 7, -5, -8, -8, -8, -8, -8, 2, 8, 8, 8, 8, 4, 0, -2, -9, -9, -5, -3, 1, 9, 9, 5, 3, -1, -7, -10, -10, -10
Offset: 1

Views

Author

William Rex Marshall, Jul 26 2012

Keywords

Comments

The eight possible orientations of the Ulam spiral can be derived from combining either A214664 or A214666 with either A214665 or A214667 as ordered pairs of coordinates.
This spiral is rotated 180 degrees from the spiral on the March 1964 cover of Scientific American.

Links

Crossrefs

Cf. A000040, A063826, A214664, A214665, A214667.
Showing 1-3 of 3 results.

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

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