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A244493
Number of oriented (0, 1, 2)-factors of the Johnson graph J(n, 2).
1
1, 6, 265, 126140, 855966441, 102526835994056, 258081861682902430193
OFFSET
2,2
COMMENTS
From James East, Jul 13 2016: (Start)
a(5) and a(6) were calculated by James Mitchell using the GAP System Packages Semigroups (see link).
a(n) is also the number of minimal size all-idempotent generating sets for the singular part of the Brauer monoid (see East-Gray paper). (End)
PROG
(C++) See Niles link.
CROSSREFS
Sequence in context: A332126 A229579 A033289 * A221900 A229773 A193983
KEYWORD
nonn,more
AUTHOR
N. J. A. Sloane, Jul 05 2014
EXTENSIONS
Name clarified by James East, Jul 14 2016
a(6) corrected and a(7) added by Ronald Niles, Apr 21 2017
a(8) added by Ronald Niles, Jun 25 2017
STATUS
approved