A229278 Number of ascending runs in {1,...,4}^n.
0, 4, 26, 144, 736, 3584, 16896, 77824, 352256, 1572864, 6946816, 30408704, 132120576, 570425344, 2449473536, 10468982784, 44560285696, 188978561024, 798863917056, 3367254360064, 14156212207616, 59373627899904, 248489627877376, 1037938976620544
Offset: 0
Links
- Alois P. Heinz, Table of n, a(n) for n = 0..1000
- Index entries for linear recurrences with constant coefficients, signature (8,-16).
Crossrefs
Column k=4 of A229079.
Programs
-
Maple
a:= n-> `if`(n=0, 0, 2^(2*n-3)*(5*n+3)): seq(a(n), n=0..30);
Formula
G.f.: -2*(3*x-2)*x/(4*x-1)^2.
a(n) = 2^(2*n-3)*(5*n+3) for n>0, a(0) = 0.