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A093732
Number of connected relations.
15
1, 211, 14221, 636331, 23679901, 805351531, 26175881341, 831358677451, 26094426008221, 814105545191851, 25320182311228861, 786251347986776971, 24394981288950302941, 756583120577782494571, 23459491617092461686781, 727330825918603925122891
OFFSET
1,2
LINKS
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 (84,-2774,47548,-462525,2575088,-7643820,9374400).
FORMULA
a(n) = 31^n - 5*16^n - 10*10^n + 20*9^n + 30*7^n - 60*6^n + 24*5^n.
G.f.: -x*(1+127*x-729*x^2-20467*x^3+107048*x^4+259620*x^5) / ( (9*x-1)*(6*x-1)*(7*x-1)*(5*x-1)*(31*x-1)*(10*x-1)*(16*x-1) ). - R. J. Mathar, Jun 09 2013
MATHEMATICA
Table[31^n - 5*16^n - 10*10^n + 20*9^n + 30*7^n - 60*6^n + 24*5^n, {n, 25}] (* T. D. Noe, May 29 2012 *)
PROG
(PARI) a(n)=31^n-5*16^n-10*10^n+20*9^n+30*7^n-60*6^n+24*5^n \\ Charles R Greathouse IV, Jun 16 2015
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Goran Kilibarda, Vladeta Jovovic, Apr 14 2004
STATUS
approved