A092797 - OEIS

%I #12 Sep 08 2022 08:45:13

%S 1,667,108817,10796275,858251401,61283936827,4147211888737,

%T 273109341611395,17736960725057401,1143745441025278987,

%U 73483870162431314257,4712360023676936085715,301901195708380781658601,19331914197940256185117147,1237580377249840094294765377

%N Number of connected relations.

%H G. C. Greubel, <a href="/A092797/b092797.txt">Table of n, a(n) for n = 1..550</a>

%H G. Kilibarda and V. Jovovic, <a href="https://arxiv.org/abs/1411.4187">Enumeration of some classes of T_0-hypergraphs</a>, arXiv:1411.4187 [math.CO], 2014.

%F a(n) = 64^n - 6*33^n - 15*19^n + 30*18^n - 10*15^n + 120*12^n - 120*11^n  + 30*10^n - 270*9^n + 360*8^n - 120*7^n.

%F G.f.: x*(54888451200*x^9 +55706052240*x^8 -14450714964*x^7 -624924*x^6 +247511131*x^5 -22659769*x^4 +564934*x^3 +10694*x^2 -461*x -1) / ((7*x -1)*(8*x -1)*(9*x -1)*(10*x -1)*(11*x -1)*(12*x -1)*(15*x -1)*(18*x -1)*(19*x -1)*(33*x -1)*(64*x -1)). - _Colin Barker_, Jul 13 2013

%t Table[64^n - 6*33^n - 15*19^n + 30*18^n - 10*15^n + 120*12^n - 120*11^n  + 30*10^n - 270*9^n + 360*8^n - 120*7^n, {n, 0, 50}] (* _G. C. Greubel_, Oct 08 2017 *)

%o (PARI) for(n=0,50, print1(64^n - 6*33^n - 15*19^n + 30*18^n - 10*15^n + 120*12^n - 120*11^n  + 30*10^n - 270*9^n + 360*8^n - 120*7^n, ", ")) \\ _G. C. Greubel_, Oct 08 2017

%o (Magma) [64^n - 6*33^n - 15*19^n + 30*18^n - 10*15^n + 120*12^n - 120*11^n  + 30*10^n - 270*9^n + 360*8^n - 120*7^n: n in [0..50]]; // _G. C. Greubel_, Oct 08 2017

%Y Cf. A005333, A001047, A002501, A002502, A093732, A093733.

%K nonn,easy

%O 1,2

%A Goran Kilibarda, _Vladeta Jovovic_, Apr 15 2004

%E More terms from _Colin Barker_, Jul 13 2013