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A008528 Coordination sequence for 4-dimensional RR-centered di-isohexagonal orthogonal lattice. 3
1, 18, 102, 318, 732, 1410, 2418, 3822, 5688, 8082, 11070, 14718, 19092, 24258, 30282, 37230, 45168, 54162, 64278, 75582, 88140, 102018, 117282, 133998, 152232, 172050, 193518, 216702, 241668 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

REFERENCES

M. O'Keeffe, Coordination sequences for lattices, Zeit. f. Krist., 210 (1995), 905-908.

LINKS

Vincenzo Librandi, Table of n, a(n) for n = 0..1000

Index entries for linear recurrences with constant coefficients, signature (4,-6,4,-1).

FORMULA

a(n) = n*(11*n^2+7) with n>0, a(0)=1 (see MAPLE line).

G.f. 1 + 6*x*(3 + 5*x + 3*x^2) / (1-x)^4. - R. J. Mathar, Sep 04 2011

MAPLE

[ seq( 11*k^3+7*k, k=1..40 ) ]; # apart from the first term

MATHEMATICA

CoefficientList[Series[1+6*x*(3+5*x+3*x^2)/(1-x)^4, {x, 0, 30}], x] (* Vincenzo Librandi, Jun 19 2012 *)

PROG

(MAGMA) I:=[1, 18, 102, 318, 732]; [n le 5 select I[n] else 4*Self(n-1)-6*Self(n-2)+4*Self(n-3)-Self(n-4): n in [1..30]]; // Vincenzo Librandi, Jun 19 2012

CROSSREFS

Sequence in context: A140198 A107600 A229326 * A020881 A223241 A197339

Adjacent sequences:  A008525 A008526 A008527 * A008529 A008530 A008531

KEYWORD

nonn,easy

AUTHOR

N. J. A. Sloane

STATUS

approved

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Last modified December 9 14:26 EST 2016. Contains 278971 sequences.