OFFSET
0,2
LINKS
Alois P. Heinz, Table of n, a(n) for n = 0..1000
Index entries for linear recurrences with constant coefficients, signature (5,-10,10,-5,1).
FORMULA
O.g.f.: -(1-x+x^2+x^4)/(-1+x)^5. - R. J. Mathar, Apr 02 2008
EXAMPLE
a(3) = 25 = (1, 3, 3, 1) dot (1, 3, 4, 3) = (1 + 9 + 12 + 3).
a(3) = 25 = (1, 6, 6, 1) dot (1, 3, 1, 0) = (1 + 18 + 6 + 0), where (1, 6, 6, 1) = row 4 of the Narayana triangle, A001263.
MAPLE
a := n-> (Matrix([[11, 4, 1, 1, 5]]). Matrix(5, (i, j)-> if (i=j-1) then 1 elif j=1 then [5, -10, 10, -5, 1][i] else 0 fi)^n)[1, 3]; seq (a(n), n=0..50); # Alois P. Heinz, Aug 14 2008
MATHEMATICA
CoefficientList[Series[-(1-x+x^2+x^4)/(-1+x)^5, {x, 0, 40}], x] (* or *) LinearRecurrence[{5, -10, 10, -5, 1}, {1, 4, 11, 25, 51}, 40] (* Harvey P. Dale, Dec 27 2016 *)
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Gary W. Adamson, Dec 29 2007
EXTENSIONS
More terms from R. J. Mathar, Apr 02 2008
More terms from Alois P. Heinz, Aug 14 2008
STATUS
approved