A008358 Crystal ball sequence for D_6 lattice.

1, 61, 853, 5577, 23673, 76389, 204205, 476113, 1000753, 1939405, 3520837, 6058009, 9966633, 15785589, 24199197, 36061345, 52421473, 74552413, 103980085, 142515049, 192285913, 255774597, 335853453

Offset

0,2

Links

T. D. Noe, Table of n, a(n) for n = 0..1000

Index entries for crystal ball sequences

J. H. Conway and N. J. A. Sloane, Low-Dimensional Lattices VII: Coordination Sequences, Proc. Royal Soc. London, A453 (1997), 2369-2389 (pdf).

Index entries for linear recurrences with constant coefficients, signature (7,-21,35,-35,21,-7,1).

Formula

G.f.: (1+54*x+447*x^2+852*x^3+447*x^4+54*x^5+x^6)/(1-x)^7. - Colin Barker, Mar 16 2012

Maple

116/45*n^6+116/15*n^5+136/9*n^4+52/3*n^3+554/45*n^2+74/15*n+1;

Mathematica

CoefficientList[Series[(1+54x+447x^2+852x^3+447x^4+54x^5+x^6)/(1-x)^7, {x, 0, 30}], x] (* Harvey P. Dale, Jan 23 2019 *)

Crossrefs

Sequence in context: A232858 A093473 A000506 * A317283 A264306 A138790

Adjacent sequences: A008355 A008356 A008357 * A008359 A008360 A008361

Keyword

nonn,easy

Author

N. J. A. Sloane and J. H. Conway

Status

approved