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 A008255 Coordination sequence T2 for feldspar. 1
 1, 4, 10, 22, 38, 56, 82, 112, 142, 182, 226, 268, 322, 380, 434, 502, 574, 640, 722, 808, 886, 982, 1082, 1172, 1282, 1396, 1498, 1622, 1750, 1864, 2002, 2144, 2270, 2422, 2578, 2716, 2882, 3052, 3202, 3382, 3566, 3728, 3922, 4120, 4294, 4502, 4714, 4900 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,2 LINKS Colin Barker, Table of n, a(n) for n = 0..1000 R. W. Grosse-Kunstleve, Coordination Sequences and Encyclopedia of Integer Sequences R. W. Grosse-Kunstleve, G. O. Brunner and N. J. A. Sloane, Algebraic Description of Coordination Sequences and Exact Topological Densities for Zeolites, Acta Cryst., A52 (1996), pp. 879-889. Sean A. Irvine, Generating Functions for Coordination Sequences of Zeolites, after Grosse-Kunstleve, Brunner, and Sloane Index entries for linear recurrences with constant coefficients, signature (1,0,2,-2,0,-1,1). FORMULA a(3*m) = 20*m^2+2, a(3*m+1) = 20*m^2+14*m+4, a(3*m+2) = 20*m^2+26*m+10. G.f.: (1+x)^3*(1+3*x^2+x^4) / ((1-x)^3*(1+x+x^2)^2). - Colin Barker, Dec 22 2015 MATHEMATICA Table[SeriesCoefficient[(1 + x)^3 (1 + 3 x^2 + x^4)/((1 - x)^3 (1 + x + x^2)^2), {x, 0, n}], {n, 0, 47}] (* Michael De Vlieger, Dec 22 2015 *) Join[{1}, LinearRecurrence[{1, 0, 2, -2, 0, -1, 1}, {4, 10, 22, 38, 56, 82, 112}, 50]] (* Vincenzo Librandi, Dec 23 2015 *) PROG (PARI) Vec((1+x)^3*(1+3*x^2+x^4)/((1-x)^3*(1+x+x^2)^2) + O(x^100)) \\ Colin Barker, Dec 22 2015 CROSSREFS Sequence in context: A009891 A301077 A341734 * A008031 A339609 A008248 Adjacent sequences: A008252 A008253 A008254 * A008256 A008257 A008258 KEYWORD nonn,easy AUTHOR Georg Thimm (mgeorg(AT)ntu.edu.sg) and Ralf W. Grosse-Kunstleve STATUS approved

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Last modified December 11 06:34 EST 2023. Contains 367717 sequences. (Running on oeis4.)