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 A022148 Coordination sequence for root lattice B_6. 4
 1, 72, 1072, 6968, 28320, 85992, 214864, 467544, 918080, 1665672, 2838384, 4596856, 7138016, 10698792, 15559824, 22049176, 30546048, 41484488, 55357104, 72718776, 94190368, 120462440, 152298960 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,2 REFERENCES R. Bacher, P. de la Harpe and B. Venkov, Series de croissance et series d'Ehrhart associees aux reseaux de racines, C. R. Acad. Sci. Paris, 325 (Series 1) (1997), 1137-1142. LINKS Vincenzo Librandi, Table of n, a(n) for n = 0..1000 M. Baake and U. Grimm, Coordination sequences for root lattices and related graphs, arXiv:cond-mat/9706122, Zeit. f. Kristallographie, 212 (1997), 253-256. FORMULA a(0) = 1; for n>0, a(n) = (8*n/15)*(58*n^4 - 65*n^3 + 180*n^2 - 85*n + 47) . - Philippe Deléham, Feb 20 2004 G.f.: (1+66*x+655*x^2+1596*x^3+1167*x^4+226*x^5+x^6)/(1-x)^6 = 1+8*x*(9+80*x+202*x^2+144*x^3+29*x^4)/(1-x)^6. - Colin Barker, Apr 13 2012 MATHEMATICA CoefficientList[Series[(1+66*x+655*x^2+1596*x^3+1167*x^4+ 226*x^5+x^6)/(1-x)^6, {x, 0, 40}], x] (* Vincenzo Librandi, Apr 20 2012 *) PROG (MAGMA) [1] cat[(8*n/15)*(58*n^4 - 65*n^3 + 180*n^2 - 85*n + 47) : n in [1..40]]; // Vincenzo Librandi, Apr 20 2012 CROSSREFS Sequence in context: A250650 A008399 A232573 * A192847 A064567 A269088 Adjacent sequences:  A022145 A022146 A022147 * A022149 A022150 A022151 KEYWORD nonn,easy AUTHOR mbaake(AT)sunelc3.tphys.physik.uni-tuebingen.de (Michael Baake) STATUS approved

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Last modified May 30 19:05 EDT 2020. Contains 334729 sequences. (Running on oeis4.)