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A256813 Number of length n+5 0..1 arrays with at most two downsteps in every 5 consecutive neighbor pairs. 1

%I

%S 63,124,245,484,956,1888,3728,7362,14539,28712,56701,111974,221128,

%T 436688,862380,1703044,3363203,6641716,13116185,25902088,51151928,

%U 101015784,199487860,393952358,777984487,1536378320,3034068649

%N Number of length n+5 0..1 arrays with at most two downsteps in every 5 consecutive neighbor pairs.

%C Column 5 of A256816.

%H R. H. Hardin, <a href="/A256813/b256813.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 2*a(n-1) -a(n-2) +2*a(n-3) -a(n-4) +2*a(n-5) -a(n-6).

%F Empirical g.f.: x*(63 - 2*x + 60*x^2 - 8*x^3 + 48*x^4 - 32*x^5) / (1 - 2*x + x^2 - 2*x^3 + x^4 - 2*x^5 + x^6). - _Colin Barker_, Jan 24 2018

%e Some solutions for n=4:

%e ..1....1....0....0....0....1....0....1....1....1....0....1....0....1....0....1

%e ..1....0....1....1....1....0....1....1....0....0....0....0....0....1....0....0

%e ..0....0....1....1....1....0....0....0....0....1....0....0....1....1....1....0

%e ..0....0....0....1....0....0....1....0....0....1....0....1....0....1....0....0

%e ..0....0....0....0....0....0....1....0....1....1....1....1....0....1....1....0

%e ..1....1....1....0....1....0....0....0....0....0....1....0....1....1....1....1

%e ..1....0....1....0....0....1....1....0....1....0....1....0....1....0....1....0

%e ..0....1....1....1....1....0....0....1....1....0....0....0....0....0....1....0

%e ..1....1....0....0....1....0....0....0....1....0....0....0....1....1....1....0

%Y Cf. A256816.

%K nonn

%O 1,1

%A _R. H. Hardin_, Apr 10 2015

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Last modified May 27 22:39 EDT 2022. Contains 354110 sequences. (Running on oeis4.)