A243515 Number of length n+2 0..6 arrays with no three elements in a row with pattern aba or abb (with a!=b) and new values 0..6 introduced in 0..6 order.
3, 5, 10, 25, 77, 279, 1134, 4979, 22981, 109453, 531458, 2610933, 12917685, 64181627, 319695982, 1594859887, 7963472189, 39784944801, 198827606706, 993846943841, 4968361974493, 24839192686975, 124188113975630
Offset: 1
Keywords
Examples
All solutions for n=3: ..0....0....0....0....0....0....0....0....0....0 ..1....0....1....0....1....1....0....1....0....0 ..2....1....2....0....2....2....0....2....1....0 ..3....2....3....1....0....3....0....0....2....0 ..1....0....0....2....3....4....1....1....3....0
Links
- R. H. Hardin, Table of n, a(n) for n = 1..210
Crossrefs
Column 6 of A243519.
Formula
Empirical: a(n) = 12*a(n-1) - 52*a(n-2) + 102*a(n-3) - 91*a(n-4) + 30*a(n-5).
Conjectures from Colin Barker, Nov 02 2018: (Start)
G.f.: x*(3 - 31*x + 106*x^2 - 141*x^3 + 60*x^4) / ((1 - x)^2*(1 - 2*x)*(1 - 3*x)*(1 - 5*x)).
a(n) = (147 + 2^(5+n) + 4*3^(1+n) + 5^n + 36*n) / 96.
(End)