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.

A281462 Number of code loops of order n.

Original entry on oeis.org

0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 5, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 16, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 80, 0
Offset: 1

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Author

Muniru A Asiru, Jan 22 2017

Keywords

Comments

A code loop is a Moufang 2-loop Q with a central subloop Z of order 2 such that Q/Z is an elementary abelian group. The library named code in LOOPS version 2.2.0, Computing with quasigroups and loops in GAP (Groups, Algorithm and Programming), contains all nonassociative code loops of order less than 65. Every code loop is a Moufang loop but not conversely. The GAP command IsCodeLoop(MoufangLoop(n,m)) gives the m-th nonassociative code loop of order n in the LOOPS Package library. Code loops of small orders were classified by G. P. Nagy and P. Vojtechovsky.
(Groups are specifically excluded from the counts.)

Examples

			a(16)=5 because all the 5 Moufang loops of order 16 are code loops;
a(32)=16 because only 16 of the 71 Moufang loops of order 32 are code loops.
		

Crossrefs

A281554 Number of nonassociative right conjugacy closed loops of order n up to isomorphism.

Original entry on oeis.org

0, 0, 0, 0, 0, 3, 0, 19, 5, 16, 0, 155, 0, 97, 17, 6317, 0, 1901, 0, 8248, 119, 10487, 0, 471995, 119, 151971, 152701
Offset: 1

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Author

Muniru A Asiru, Jan 24 2017

Keywords

Comments

For a groupoid Q and x in Q, define the right (left) translation map R_x: Q->Q by yR_x=yx (L_x: Q->Q by yL_x=xy). A loop is a groupoid Q with neutral element 1 in which all translations are bijections in Q. A loop Q is right conjugacy closed if (R_x)^(-1)R_yR_x is a right translation for every x, y in Q. Since any finite loop of order n < 5 is a group, then nonassociative right conjugacy closed loops exist when the order n > 5. In the literature, every nonassociative right conjugacy closed loop of order n can be represented as a union of certain conjugacy classes of a transitive group of degree n. The number of nonassociative right conjugacy closed loops of order n up to isomorphism were summarized in LOOPS version 3.3.0, Computing with quasigroups and loops in GAP (Groups, Algorithm and Programming).

Examples

			a(6)=3 because there are 3 nonassociative right conjugacy closed loops of order 6 and a(8)=19 because there are 19 nonassociative right conjugacy closed loops of order 8.
		

Crossrefs

A282530 Number of finite FRUTE loops of order n up to isomorphism.

Original entry on oeis.org

0, 0, 0, 0, 0, 0, 0, 2, 0, 0, 0, 0, 0, 0, 0, 6, 0, 0, 0, 0, 0, 0, 0, 2, 0, 0, 0, 0, 0, 0, 0, 27, 0, 0, 0, 0, 0, 0, 0, 2, 0, 0, 0, 0, 0, 0, 0, 5, 0, 0, 0, 0, 0, 0, 0, 2, 0, 0, 0, 0, 0, 0, 0
Offset: 1

Views

Author

Muniru A Asiru, Feb 17 2017

Keywords

Comments

For a groupoid Q and x in Q, define the right (left) translation map R_x: Q->Q by yR_x=yx (L_x: Q->Q by yL_x=xy). A loop is a groupoid Q with neutral element 1 in which all translations are bijections in Q. A loop Q is called a FRUTE loop if it satisfies the identity (x.xy)z=(y.xz)x for all x, y, z in Q. The smallest associative non-commutative finite FRUTE loop is of order 8, the quaternion group having 8 elements.

Examples

			a(8)=2 since there are 2 FRUTE loops of order 8, one of which is the quaternion group of order 8 and a(16)=6 since there are 6 FRUTE loops of order 16.
		

Crossrefs

Showing 1-3 of 3 results.