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.

A058153 Number of labeled monoids of order n.

Original entry on oeis.org

1, 4, 33, 624, 20610, 1252032, 129552080, 63141932606
Offset: 1

Views

Author

Christian G. Bower, Nov 14 2000

Keywords

Links

Crossrefs

a(n) = A058154(n)*n.

Extensions

a(8) from Christian G. Bower, Dec 28 2006

A058158 Triangle read by rows: T(n,k) is the number of labeled monoids of order n with k idempotents and a fixed identity.

Original entry on oeis.org

1, 1, 1, 1, 6, 4, 4, 45, 72, 35, 6, 528, 1308, 1676, 604, 80, 19935, 39700, 70170, 62060, 16727, 120, 3599436, 1969470, 3829000, 5167800, 3260382, 681232, 2760, 6085914205, 281840664, 294812385, 481221020, 482447637, 228315640, 38187291
Offset: 1

Views

Author

Christian G. Bower, Nov 14 2000

Keywords

Examples

			Triangle begins:
   1;
   1,     1;
   1,     6,     4;
   4,    45,    72,    35;
   6,   528,  1308,  1676,   604;
  80, 19935, 39700, 70170, 62060, 16727;
  ...

Links

Crossrefs

Row sums give A058154.
Column 1: A058163.
Main diagonal is A351730(n-1).
Cf. A058137 (isomorphism classes), A058157, A058160 (commutative), A058166.

Formula

T(n,k) = A058157(n,k)/n.

Extensions

a(30)-a(36) from Andrew Howroyd, Feb 15 2022
Showing 1-2 of 2 results.

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

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