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A245731 Number of connected labeled transitive relations on an n-set. 2

%I

%S 1,2,9,109,2647,110481,7291543,726434549,106312974249,22465350835849,

%T 6771847676632679,2883916106465622053,1720792953946798909927,

%U 1427968172285571102335605,1637002867699829205840095585,2577011453377960519672777065693,5541005747990556022043234479371823,16195114271558690956785525865003941945,64068293759315414337050896928055465961863

%N Number of connected labeled transitive relations on an n-set.

%F E.g.f.: log(A(x + exp(x) - 1)) + 1 where A(x) is the e.g.f. for A001035.

%e a(2) = 9. There are 13 transitive relations on the set {1,2}. Four of these are not connected: {}, {(1,1)}, {(2,2)}, {(1,1),(2,2)}. 13-4=9.

%Y Cf. A001035, A006905.

%K nonn

%O 0,2

%A _Geoffrey Critzer_, Jul 30 2014

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Last modified December 1 16:44 EST 2021. Contains 349430 sequences. (Running on oeis4.)