A076113 a(n) = n^(n*(n-1)/2).

1, 1, 2, 27, 4096, 9765625, 470184984576, 558545864083284007, 19342813113834066795298816, 22528399544939174411840147874772641, 1000000000000000000000000000000000000000000000, 1890591424712781041871514584574319778449301246603238034051

Offset: 0

Author

Amarnath Murthy, Oct 09 2002

Keywords

• easy
• nonn

Comments

Number of labeled commutative idempotent groupoids with n elements. [edited by Michel Marcus, Jul 10 2025]

Product of terms in n-th row of A076112.

Links

• Alois P. Heinz, Table of n, a(n) for n = 0..36
• Index entries for sequences related to groupoids

Crossrefs

Cf. A000169, A002489, A006125, A023037, A030257, A076112, A090588.

Programs

PARI

a(n) = n^(n*(n-1)/2); \\ Joerg Arndt, Nov 04 2013

Extensions

More terms from Antonio G. Astudillo (afg_astudillo(AT)lycos.com), Apr 20 2003

a(0)=1 prepended by Alois P. Heinz, Jun 30 2022