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A002638 a(n) = (number of nonisomorphic nontransitive prime tournaments on n nodes) - Moebius(n).
(Formerly M0913 N0345)
2
-1, 1, 2, 3, 12, 52, 456, 6873, 191532, 9733032, 903753248, 154108311046, 48542114686912, 28401423719121392, 31021002160355166800, 63530415842308265086523, 244912778438520759443245824, 1783398846284777975419599903948, 24605641171260376770598003978281472 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,3
REFERENCES
N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 (includes this sequence).
N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
LINKS
Pontus von Brömssen, Table of n, a(n) for n = 1..76
J. W. Moon and M. Goldberg, On the composition of two tournaments, Duke Mathematical Journal, vol.37, no.2 (1970), pp.323-332. (subscription required)
J. W. Moon and M. Goldberg, On the composition of two tournaments, Duke Mathematical Journal 37.2 (1970): 323-332. [Annotated scans of pages 331 and 332 only]
FORMULA
a(1)=-1, a(n) = A000568(n) - Sum_{d|n, d!=1, d!=n} (a(d) * A000568(n / d). - Sean A. Irvine, Oct 19 2015
a(n) = A259106(n) - A008683(n). - Pontus von Brömssen, Oct 03 2020
CROSSREFS
Sequence in context: A307957 A307956 A358716 * A027072 A083746 A025231
KEYWORD
sign
AUTHOR
EXTENSIONS
Definition clarified by N. J. A. Sloane, Jun 23 2015
More terms from Sean A. Irvine, Oct 19 2015
a(19) from Pontus von Brömssen, Oct 03 2020
STATUS
approved

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Last modified March 29 08:45 EDT 2024. Contains 371267 sequences. (Running on oeis4.)