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A090602
Number of n-element labeled groupoids with an identity.
3
0, 1, 4, 243, 1048576, 762939453125, 170581728179578208256, 18562115921017574302453163671207, 1427247692705959881058285969449495136382746624, 106111661199647248543687855752712667991103904330482569981872649
OFFSET
0,3
COMMENTS
Also labeled groupoids with an absorbant (zero) element.
FORMULA
a(n) = n^((n-1)^2+1).
a(n) = A090603(n)*n.
PROG
(PARI) a(n) = n^((n-1)^2+1) \\ Andrew Howroyd, Jan 23 2022
CROSSREFS
Cf. A090601 (isomorphism classes), A090603.
Sequence in context: A091792 A300595 A320418 * A180722 A087587 A346919
KEYWORD
nonn
AUTHOR
Christian G. Bower, Dec 05 2003
EXTENSIONS
a(0)=0 prepended and a(9) added by Andrew Howroyd, Jan 23 2022
STATUS
approved