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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] Index entries for sequences related to tournaments 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 Cf. A000568, A008683, A259106. Sequence in context: A307957 A307956 A358716 * A027072 A083746 A025231 Adjacent sequences: A002635 A002636 A002637 * A002639 A002640 A002641 KEYWORD sign AUTHOR N. J. A. Sloane 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 September 10 09:32 EDT 2024. Contains 375786 sequences. (Running on oeis4.)