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A222867 Number of n X 1 0..5 arrays with no element equal to another at a city block distance of exactly two, and new values 0..5 introduced in row major order. 1

%I #9 Aug 16 2018 08:59:21

%S 1,2,3,7,20,67,254,1057,4700,21847,104474,508477,2501480,12386227,

%T 61570694,306778297,1530678260,7643776207,38190084914,190864134517,

%U 954061999040,4769534367787,23845345743134,119219752001137

%N Number of n X 1 0..5 arrays with no element equal to another at a city block distance of exactly two, and new values 0..5 introduced in row major order.

%C Column 1 of A222871.

%H R. H. Hardin, <a href="/A222867/b222867.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 11*a(n-1) - 41*a(n-2) + 61*a(n-3) - 30*a(n-4) for n>6.

%F Empirical g.f.: x*(1 + x)*(1 - 10*x + 32*x^2 - 37*x^3 + 11*x^4) / ((1 - x)*(1 - 2*x)*(1 - 3*x)*(1 - 5*x)). - _Colin Barker_, Aug 16 2018

%e All solutions for n=3:

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

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

%e ..2....1....1

%Y Cf. A222871.

%K nonn

%O 1,2

%A _R. H. Hardin_, Mar 07 2013

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Last modified February 26 09:21 EST 2024. Contains 370338 sequences. (Running on oeis4.)