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Number of connected relations.
(Formerly M5336 N2323)
17

%I M5336 N2323 #32 Jan 29 2022 01:05:52

%S 1,65,1795,36317,636331,10365005,162470155,2495037197,37898120011,

%T 572284920845,8614868501515,129467758660877,1943971108806091,

%U 29175170378428685,437752102106036875,6567275797761209357

%N Number of connected relations.

%D N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 (includes this sequence).

%D N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).

%H T. D. Noe, <a href="/A002502/b002502.txt">Table of n, a(n) for n=1..100</a>

%H G. Kreweras, <a href="http://gallica.bnf.fr/ark:/12148/bpt6k480296q/f583.image">Inversion des polynômes de Bell bidimensionnels et application au dénombrement des relations binaires connexes</a>. C. R. Acad. Sci. Paris Ser. A-B 268 1969 A577-A579.

%H <a href="/index/Rec#order_05">Index entries for linear recurrences with constant coefficients</a>, signature (38,-539,3622,-11640,14400).

%F 15^n-4*8^n-3*6^n+12*5^n-6*4^n. - Goran Kilibarda, _Vladeta Jovovic_, Apr 14 2004

%F G.f. x*( -1-27*x+136*x^2+480*x^3 ) / ( (6*x-1)*(5*x-1)*(15*x-1)*(4*x-1)*(8*x-1) ).

%F - _R. J. Mathar_, Jun 09 2013

%t LinearRecurrence[{38,-539,3622,-11640,14400},{1,65,1795,36317,636331},20] (* _Harvey P. Dale_, Mar 24 2017 *)

%Y Cf. A005333, A001047, A002501, A093732, A093733.

%Y A diagonal of A262307.

%K nonn,nice,easy

%O 1,2

%A _N. J. A. Sloane_

%E More terms from Goran Kilibarda, _Vladeta Jovovic_, Apr 14 2004