OFFSET
0,3
LINKS
Index entries for linear recurrences with constant coefficients, signature (3,-2,0,-1,1).
FORMULA
G.f.: x*(1 + x + x^2)/((-1 + x)^2*(1 - x - x^2 - x^3)).
a(n) = 3*a(n-1) - 2*a(n-2) - a(n-4) + a(n-5).
a(n) = A221949(n+2)-1 for n >= 0.
MATHEMATICA
maxDiff = 3;
t = Map[Length[Select[Map[{#, Max[Differences[#]]} &,
Drop[Subsets[Range[#]], # + 1]], #[[2]] <= maxDiff &]] &, Range[16]]
FindGeneratingFunction[%, x]
FindLinearRecurrence[t]
LinearRecurrence[{3, -2, 0, -1, 1}, {0, 1, 4, 11, 25}, 45]
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Clark Kimberling, Aug 24 2022
STATUS
approved