A244872 - OEIS

%I #17 Nov 01 2021 11:47:58

%S 1,15,114,569,2138,6562,17329,40765,87512,174452,327137,582784,993895,

%T 1632561,2595510,4009958,6040323,8895861,12839284,18196419,25366968,

%U 34836428,47189231,63123163,83465122,109188274,141430667,181515362,230972141,291560851,365296444

%N Number of magic labelings with magic sum n of 4th graph shown in link.

%H N. J. A. Sloane, <a href="/A244869/a244869.jpg">Graphs for A244869-A244876.</a>

%H R. P. Stanley, <a href="/A002721/a002721.pdf">Examples of Magic Labelings</a>, Unpublished Notes, 1973 [Cached copy, with permission]

%H <a href="/index/Rec#order_09">Index entries for linear recurrences with constant coefficients</a>, signature (7, -20, 28, -14, -14, 28, -20, 7, -1).

%F G.f.: (1+8*x+29*x^2+43*x^3+29*x^4+8*x^5+x^6)/((1-x)^8*(1+x)).

%F a(n) = 17*n^7/1440 + 119*n^6/960 + 28*n^5/45 + 721*n^4/384 + 5243*n^3/1440 + 721*n^2/160 + 129*n/40 + (-1)^n/256 + 255/256. [_Bruno Berselli_, Jul 08 2014]

%t Table[17 n^7/1440 + 119 n^6/960 + 28 n^5/45 + 721 n^4/384 + 5243 n^3/1440 + 721 n^2/160 + 129 n/40 + (-1)^n/256 + 255/256, {n, 0, 30}]

%t LinearRecurrence[{7,-20,28,-14,-14,28,-20,7,-1},{1,15,114,569,2138,6562,17329,40765,87512},40] (* _Harvey P. Dale_, Nov 01 2021 *)

%Y Cf. A244869-A244876.

%K nonn,easy

%O 0,2

%A _N. J. A. Sloane_, Jul 08 2014