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A009945

Coordination sequence for NiAs(2), As position.

1, 6, 18, 42, 74, 114, 162, 222, 290, 366, 450, 546, 650, 762, 882, 1014, 1154, 1302, 1458, 1626, 1802, 1986, 2178, 2382, 2594, 2814, 3042, 3282, 3530, 3786, 4050, 4326, 4610, 4902, 5202, 5514, 5834, 6162, 6498, 6846, 7202, 7566, 7938, 8322, 8714

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OFFSET

0,2

REFERENCES

Gmelin Handbook of Inorg. and Organomet. Chem., 8th Ed., 1994, TYPIX search code (194) hP4.

LINKS

Vincenzo Librandi, 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 (2,-1,0,1,-2,1).

FORMULA

a(0)=1, a(4n)=2*((6n)^2+1), a(4n+2)=18*(2n+1)^2, a(2n+1)=6*(3n^2+3n+1). - Ralf Stephan, Mar 07 2004

G.f.: -(x^3+x^2+3*x+1)*(x^3+3*x^2+x+1) / ((x-1)^3*(x+1)*(x^2+1)). - Colin Barker, Aug 30 2013

MATHEMATICA

CoefficientList[Series[-(x^3 + x^2 + 3 x + 1) (x^3 + 3 x^2 + x + 1)/((x - 1)^3 (x + 1) (x^2 + 1)), {x, 0, 50}], x] (* Vincenzo Librandi, Oct 15 2013 *)

CROSSREFS

Sequence in context: A074837 A286308 A015942 * A270683 A011930 A330844

Adjacent sequences: A009942 A009943 A009944 * A009946 A009947 A009948

KEYWORD

nonn,easy

AUTHOR

Ralf W. Grosse-Kunstleve

STATUS

approved

URL: https://oeis.org/A009945

⇱ A009945 - OEIS