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.

A320491 Number of connected edge-self-dual nets with n nodes.

Original entry on oeis.org

1, 2, 0, 4, 13, 98, 748, 9982, 205290, 6546960, 352371887, 29668304472, 4303531187466, 985391751078694, 391866509275972993, 248491878411568471280, 274544424465100159954078, 488310442484985365942048784, 1513516279388226593561422201905
Offset: 0

Views

Author

N. J. A. Sloane, Oct 25 2018

Keywords

Links

Crossrefs

Cf. A004103 (nets), A004106 (edge-self-dual), A320489 (connected nets).

Programs

Formula

a(2*n-1) = b(2*n-1), a(2*n) = b(2*n) - (A320489(n) - a(n))/2 where b is the Inverse Euler transform of A004106.

Extensions

Dead sequence restored, corrected and extended by Andrew Howroyd, Jan 28 2020

A320994 Number of connected point-self-dual nets with 2n nodes.

Original entry on oeis.org

1, 2, 37, 3264, 1798306, 7066174625, 208496688495494, 47481277563116098111, 85161165189313899034899294, 1221965295353715648352925546245057, 142024241427456183309163988600775633635361, 135056692113925953789612785828652550808044930178235
Offset: 0

Views

Author

N. J. A. Sloane, Oct 26 2018

Keywords

Links

Crossrefs

Cf. A004103 (nets), A004105 (point-self-dual on 2n nodes), A320489 (connected nets).

Programs

Formula

a(2*n-1) = b(2*n-1) - A320489(2*n-1)/2, a(2*n) = b(2*n) - (A320489(2*n)-a(n))/2 where b is the Inverse Euler transform of A004105. - Andrew Howroyd, Jan 27 2020

Extensions

a(0)=1 prepended and terms a(7) and beyond from Andrew Howroyd, Jan 26 2020

A320995 Number of connected self-dual nets with 2n nodes.

Original entry on oeis.org

1, 0, 5, 136, 24162, 29488085, 286615837574, 21717610066598371, 12980514969049888065118, 62082684164458190567999459967, 2405195234525224724112302276711929089, 762399076229936058613587754015434541854738381
Offset: 0

Views

Author

N. J. A. Sloane, Oct 26 2018

Keywords

Links

Crossrefs

Cf. A004103 (not necessarily connected nets), A004107 (self-dual), A320489 (connected nets).

Programs

Formula

a(2*n-1) = b(2*n-1) - A320489(2*n-1)/2, a(2*n) = b(2*n) - (A320489(2*n)-a(n))/2 where b is the Inverse Euler transform of A004107. - Andrew Howroyd, Jan 27 2020

Extensions

a(0)=1 prepended and terms a(7) and beyond from Andrew Howroyd, Jan 26 2020
Showing 1-3 of 3 results.

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

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