A132158 a(3n+k) = 3a(3n+k-1)-3a(3n+k-2)+2a(3n+k-3) for k = 0,1; a(3n+2) = 3a(3n-1)-3a(3n-2), with a(0) = 0,a(1) = 1,a(2) = 3.
0, 1, 3, 6, 11, 15, 24, 49, 75, 126, 251, 375, 624, 1249, 1875, 3126, 6251, 9375
Offset: 0
Keywords
Links
- Index entries for linear recurrences with constant coefficients, signature (1, -1, 5, -5, 5).
Programs
-
Mathematica
LinearRecurrence[{1, -1, 5, -5, 5},{0, 1, 3, 6, 11},18] (* Ray Chandler, Sep 23 2015 *)
Formula
Sequence is identical to its third differences in absolute values.
G.f.:-x*(x+1)*(3*x^2+x+1)/((x^2-x+1)*(5*x^3-1)) [From Maksym Voznyy (voznyy(AT)mail.ru), Aug 12 2009]