A092795 Number of connected relations.

1, 67, 1993, 43891, 836521, 14764627, 249723433, 4123297651, 67157947561, 1085384064787, 17464790421673, 280328391247411, 4493290901135401, 71964955947764947, 1152089156508284713, 18439265231953981171, 295080697103288816041, 4721762414918959913107

Offset

1,2

Links

G. C. Greubel, Table of n, a(n) for n = 1..825

G. Kilibarda and V. Jovovic, Enumeration of some classes of T_0-hypergraphs, arXiv:1411.4187 [math.CO], 2014.

Index entries for linear recurrences with constant coefficients, signature (43,-701,5477,-20658,30240).

Formula

a(n) = 16^n - 4*9^n - 3*7^n + 12*6^n - 6*5^n.

G.f.: x*(318*x^3+187*x^2-24*x-1) / ((5*x-1)*(6*x-1)*(7*x-1)*(9*x-1)*(16*x-1)). - Colin Barker, Jul 13 2013

Mathematica

Table[16^n - 4*9^n - 3*7^n + 12*6^n - 6*5^n, {n, 1, 50}] (* G. C. Greubel, Oct 08 2017 *)

Prog

(PARI) for(n=1, 50, print1(16^n - 4*9^n - 3*7^n + 12*6^n - 6*5^n, ", ")) \\ G. C. Greubel, Oct 08 2017
(Magma) [16^n - 4*9^n - 3*7^n + 12*6^n - 6*5^n: n in [1..50]]; // G. C. Greubel, Oct 08 2017

Crossrefs

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

Sequence in context: A157665 A231193 A078850 * A017783 A017730 A078953

Adjacent sequences: A092792 A092793 A092794 * A092796 A092797 A092798

Keyword

nonn,easy

Author

Goran Kilibarda, Vladeta Jovovic, Apr 15 2004

Extensions

More terms from Colin Barker, Jul 13 2013

Status

approved