OFFSET
0,2
COMMENTS
Source: the De Loera et al. article and the Haws website listed in A160747.
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 0..10000
Index entries for linear recurrences with constant coefficients, signature (7,-21,35,-35,21,-7,1).
FORMULA
From R. J. Mathar, Dec 16 2009: (Start)
a(n) = 1+24/5*n+38/3*n^3+207/20*n^2+61/6*n^4+68/15*n^5+89/60*n^6.
a(n) = 1+ n*(n+1)*(89*n^4+183*n^3+427*n^2+333*n+288)/60. (End)
MATHEMATICA
CoefficientList[Series[(1+38x+262x^2+475x^3+254x^4+37x^5+x^6)/(1-x)^7, {x, 0, 40}], x] (* or *) LinearRecurrence[{7, -21, 35, -35, 21, -7, 1}, {1, 45, 556, 3457, 14317, 45565, 120772}, 40] (* Harvey P. Dale, Nov 27 2016 *)
PROG
(Magma) [1+ n*(n+1)*(89*n^4+183*n^3+427*n^2+333*n+288)/60: n in [0..30]]; // Vincenzo Librandi, Sep 19 2011
(PARI) x='x+O('x^30); Vec((1+38*x+262*x^2+475*x^3+254*x^4+37*x^5+x^6)/(1-x)^7) \\ G. C. Greubel, Apr 28 2018
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
N. J. A. Sloane, Nov 18 2009
STATUS
approved
