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 A009926 Coordination sequence for CaF2(2), Ca position. 1
 1, 8, 12, 48, 42, 128, 92, 248, 162, 408, 252, 608, 362, 848, 492, 1128, 642, 1448, 812, 1808, 1002, 2208, 1212, 2648, 1442, 3128, 1692, 3648, 1962, 4208, 2252, 4808, 2562, 5448, 2892, 6128, 3242, 6848, 3612, 7608, 4002, 8408, 4412, 9248, 4842 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,2 REFERENCES Gmelin Handbook of Inorg. and Organomet. Chem., 8th Ed., 1994, TYPIX search code (225) cF12. LINKS Sean A. Irvine, 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. Index entries for linear recurrences with constant coefficients, signature (0, 3, 0, -3, 0, 1). FORMULA From Colin Barker, Sep 09 2014: (Start) a(n) = (-2*(-5+(-1)^n)-5*(-3+(-1)^n)*n^2)/4 for n>0. a(n) = 3*a(n-2)-3*a(n-4)+a(n-6) for n>6. G.f.: -(x^6+8*x^5+9*x^4+24*x^3+9*x^2+8*x+1) / ((x-1)^3*(x+1)^3). (End) G.f.: (1+8*x+9*x^2+24*x^3+9*x^4+8*x^5+x^6) / (1-x^2)^3 MATHEMATICA Join[{1}, LinearRecurrence[{0, 3, 0, -3, 0, 1}, { 8, 12, 48, 42, 128, 92}, 44]] (* Georg Fischer, Feb 27 2019 *) CROSSREFS Sequence in context: A032410 A077101 A229497 * A022668 A286360 A212815 Adjacent sequences:  A009923 A009924 A009925 * A009927 A009928 A009929 KEYWORD nonn AUTHOR STATUS approved

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Last modified April 20 23:46 EDT 2021. Contains 343143 sequences. (Running on oeis4.)