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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
OFFSET
0,2
REFERENCES
Gmelin Handbook of Inorg. and Organomet. Chem., 8th Ed., 1994, TYPIX search code (225) cF12.
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
KEYWORD
nonn
STATUS
approved