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.

A079184 Number of isomorphism classes of non-commutative closed binary operations on a set of order n, listed by class size.

Original entry on oeis.org

0, 4, 2, 2, 8, 70, 3121, 2, 1, 14, 22, 275, 467, 48306, 178888897
Offset: 1

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Author

Christian van den Bosch (cjb(AT)cjb.ie), Jan 03 2003

Keywords

Comments

A079184(n)+A079185(n)=A079171(n).
Elements per row: 1,2,4,8,16,30,... (given by A027423, number of positive divisors of n!)
First four rows: 0; 4,2; 2,8,70,3121; 2,1,14,22,275,467,48306,178888897
A079176(x) is equal to the sum of the products of each element in row x of this sequence and the corresponding element of A079210.
The sum of each row n is given by A079177(n).

Links

Crossrefs

Cf. A079182, A079183, A079185.

A030255 Number of nonisomorphic commutative groupoids with no symmetry.

Original entry on oeis.org

1, 1, 4, 116, 43428, 254197133
Offset: 0

Views

Author

Christian G. Bower

Keywords

Links

Crossrefs

a(n) = A079185(n, A027423(n)). Cf. A001425.
Showing 1-2 of 2 results.

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

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