A092797 Number of connected relations.

1, 667, 108817, 10796275, 858251401, 61283936827, 4147211888737, 273109341611395, 17736960725057401, 1143745441025278987, 73483870162431314257, 4712360023676936085715, 301901195708380781658601, 19331914197940256185117147, 1237580377249840094294765377

Offset: 1

Author

Goran Kilibarda, Vladeta Jovovic, Apr 15 2004

Keywords

• nonn
• easy

Links

• G. C. Greubel, Table of n, a(n) for n = 1..550
• G. Kilibarda and V. Jovovic, Enumeration of some classes of T_0-hypergraphs, arXiv:1411.4187 [math.CO], 2014.

Crossrefs

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

Programs

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

Mathematica

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 *)

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

Formula

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.

G.f.: x*(54888451200*x^9 [phone]*x^8 -14450714964*x^7 -624924*x^6 [phone]*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

Extensions

More terms from Colin Barker, Jul 13 2013