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.

Previous Showing 11-14 of 14 results.

A268563 Number of immersions of unoriented circle into oriented sphere with 2n double points such that two different choices of orientation of the circle are related by geotopy.

Original entry on oeis.org

1, 1, 5, 33, 249, 2036, 17572, 157676, 1457037
Offset: 0

Views

Author

N. J. A. Sloane, Mar 02 2016

Keywords

Crossrefs

Formula

a(n) = 2 * A008987(2*n) - A008986(2*n). - Andrey Zabolotskiy, Jun 05 2024

Extensions

Name clarified and a(0), a(6)-a(8) added using formula by Andrey Zabolotskiy, Jun 07 2024

A268564 Number of immersions of unoriented circle into oriented sphere with 2n double points such that two different choices of orientation of the circle are not related by geotopy.

Original entry on oeis.org

0, 1, 16, 555, 27155, 1624602, 110848296, 8306916404, 667683029392
Offset: 0

Views

Author

N. J. A. Sloane, Mar 02 2016

Keywords

Crossrefs

Formula

a(n) = A008986(2*n) - A008987(2*n). - Andrey Zabolotskiy, Jun 05 2024

Extensions

Name clarified and a(0), a(6)-a(8) added using formula by Andrey Zabolotskiy, Jun 08 2024

A268565 Number of achiral immersions of oriented circle into oriented sphere with 2n double points.

Original entry on oeis.org

1, 1, 5, 15, 97, 592, 4488, 35314, 295379
Offset: 0

Views

Author

N. J. A. Sloane, Mar 03 2016

Keywords

Crossrefs

Formula

a(n) = 2 * A008988(2*n) - A008986(2*n). - Andrey Zabolotskiy, Jun 05 2024

Extensions

Name clarified and a(0), a(6)-a(8) added using formula by Andrey Zabolotskiy, Jun 08 2024

A268566 Number of chiral immersions of oriented circle into oriented sphere with 2n double points.

Original entry on oeis.org

0, 1, 16, 564, 27231, 1625324, 110854838, 8306977585, 667683610221
Offset: 0

Views

Author

N. J. A. Sloane, Mar 03 2016

Keywords

Crossrefs

Formula

a(n) = A008986(2*n) - A008988(2*n). - Andrey Zabolotskiy, Jun 05 2024

Extensions

Name clarified and a(0), a(6)-a(8) added using formula by Andrey Zabolotskiy, Jun 08 2024
Previous Showing 11-14 of 14 results.