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A257060 Number of length n 1..(6+1) arrays with every leading partial sum divisible by 2 or 3.

%I A257060 #8 Dec 20 2018 17:36:46
%S A257060 4,18,81,364,1636,7353,33048,148534,667585,3000456,13485528,60610609,
%T A257060 272413948,1224362538,5502888657,24732693652,111160914460,
%U A257060 499611933801,2245502257776,10092393813166,45360191702017,203871056692176
%N A257060 Number of length n 1..(6+1) arrays with every leading partial sum divisible by 2 or 3.
%H A257060 R. H. Hardin, <a href="/A257060/b257060.txt">Table of n, a(n) for n = 1..210</a>
%F A257060 Empirical: a(n) = 4*a(n-1) + 2*a(n-2) +a(n-3).
%F A257060 Empirical g.f.: x*(4 + 2*x + x^2) / (1 - 4*x - 2*x^2 - x^3). - _Colin Barker_, Dec 20 2018
%e A257060 Some solutions for n=4:
%e A257060 ..4....4....3....4....2....2....3....4....3....2....4....6....6....3....4....6
%e A257060 ..4....2....3....2....6....2....7....2....5....4....5....4....4....3....5....2
%e A257060 ..6....2....3....2....2....4....5....3....7....3....7....6....5....6....7....4
%e A257060 ..2....1....6....4....6....1....3....3....7....1....6....2....7....3....4....4
%Y A257060 Column 6 of A257062.
%K A257060 nonn
%O A257060 1,1
%A A257060 _R. H. Hardin_, Apr 15 2015