OFFSET
0,2
LINKS
T. D. Noe, Table of n, a(n) for n = 0..1000
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
KEYWORD
nonn,easy
AUTHOR
STATUS
approved