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A251418 Floor((n^2+7n-23)/14). 2

%I #23 Sep 08 2022 08:46:10

%S -2,-2,-1,0,1,2,3,5,6,8,10,12,14,16,19,21,24,27,30,33,36,40,43,47,51,

%T 55,59,63,68,72,77,82,87,92,97,103,108,114,120,126,132,138,145,151,

%U 158,165,172,179,186,194,201,209,217,225,233,241,250,258,267,276

%N Floor((n^2+7n-23)/14).

%C This is conjectured to be the value of the dominance number of the triangle grid graph for n >= 14 - see A251419.

%H Colin Barker, <a href="/A251418/b251418.txt">Table of n, a(n) for n = 0..1000</a>

%H Stan Wagon, <a href="http://www.jstor.org/stable/10.4169/college.math.j.45.4.278">Graph Theory Problems from Hexagonal and Traditional Chess</a>, The College Mathematics Journal, Vol. 45, No. 4, September 2014 pp. 278-287.

%H <a href="/index/Rec#order_09">Index entries for linear recurrences with constant coefficients</a>, signature (2,-1,0,0,0,0,1,-2,1).

%F G.f.: (3*x^8-3*x^7-x^2-2*x+2) / ((x-1)^3*(x^6+x^5+x^4+x^3+x^2+x+1)). - _Colin Barker_, Jul 10 2015

%t Table[Floor[(n^2 + 7 n - 23) / 14], {n, 0, 80}] (* _Vincenzo Librandi_, Dec 04 2014 *)

%t LinearRecurrence[{2,-1,0,0,0,0,1,-2,1},{-2,-2,-1,0,1,2,3,5,6},60] (* _Harvey P. Dale_, Mar 19 2020 *)

%o (Magma) [Floor((n^2+7*n-23)/14): n in [0..60]]; // _Vincenzo Librandi_, Dec 04 2014

%o (PARI) Vec((3*x^8-3*x^7-x^2-2*x+2)/((x-1)^3*(x^6+x^5+x^4+x^3+x^2+x+1)) + O(x^100)) \\ _Colin Barker_, Jul 10 2015

%Y Cf. A251419.

%K sign,easy

%O 0,1

%A _N. J. A. Sloane_, Dec 04 2014

%E More terms from _Vincenzo Librandi_, Dec 04 2014

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Last modified March 28 08:22 EDT 2024. Contains 371236 sequences. (Running on oeis4.)