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

Author

Goran Kilibarda, Vladeta Jovovic, Apr 15 2004

Keywords

• nonn
• easy

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).

Crossrefs

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

Programs

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

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 *)
LinearRecurrence[{43,-701,5477,-20658,30240},{1,67,1993,43891,836521},20] (* Harvey P. Dale, May 24 2025 *)

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

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

Extensions

More terms from Colin Barker, Jul 13 2013