A269882 - OEIS

%I #8 Jan 29 2019 15:43:26

%S 6,432,11280,250992,5125008,99482544,1867222224,34216907760,

%T 615877284624,10931855797296,191890772032848,3337772595455088,

%U 57618604390530960,988280162421210288,16858064726292134352,286196732519053403376

%N Number of n X 2 0..5 arrays with some element plus some horizontally, diagonally, antidiagonally or vertically adjacent neighbor totalling five exactly once.

%H R. H. Hardin, <a href="/A269882/b269882.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 30*a(n-1) - 197*a(n-2) - 420*a(n-3) - 196*a(n-4) for n>5.

%F Empirical g.f.: 6*x*(1 - x)^2*(1 + 44*x + 4*x^2) / (1 - 15*x - 14*x^2)^2. - _Colin Barker_, Jan 29 2019

%e Some solutions for n=3:

%e ..5..5. .1..1. .0..4. .1..2. .4..3. .3..3. .2..4. .4..2. .0..2. .1..4

%e ..5..3. .3..2. .4..0. .2..1. .4..3. .1..0. .1..5. .4..5. .1..0. .3..3

%e ..1..2. .4..5. .5..4. .3..0. .0..1. .2..3. .1..1. .3..2. .1..5. .3..4

%Y Column 2 of A269888.

%K nonn

%O 1,1

%A _R. H. Hardin_, Mar 06 2016