

A002638


a(n) = (number of nonisomorphic nontransitive prime tournaments on n nodes)  Moebius(n).
(Formerly M0913 N0345)


1



1, 1, 2, 3, 12, 52, 456, 6873, 191532, 9733032, 903753248, 154108311046, 48542114686912, 28401423719121392, 31021002160355166800, 63530415842308265086523, 244912778438520759443245824, 1783398846284777975419599903948
(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

Table of n, a(n) for n=1..18.
J. W. Moon and M. Goldberg, On the composition of two tournaments, Duke Mathematical Journal, vol.37, no.2 (1970), pp.323332. (subscription required)
J. W. Moon and M. Goldberg, On the composition of two tournaments, Duke Mathematical Journal 37.2 (1970): 323332. [Annotated scans of pages 331 and 332 only]
Index entries for sequences related to tournaments


FORMULA

a(1)=1, a(n) = A000568(n)  Sum_{dn, d!=1, d!=n} (a(d) * A000568(n / d).  Sean A. Irvine, Oct 19 2015


CROSSREFS

Cf. A000568, A008683.
Sequence in context: A232864 A307957 A307956 * 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


STATUS

approved



