cp's OEIS Frontend

A220250 Sum of neighbor maps: number of nX2 binary arrays indicating the locations of corresponding elements equal to the sum mod 3 of their king-move neighbors in a random 0..2 nX2 array.

%I A220250 #10 Jul 23 2025 00:58:58
%S A220250 2,16,48,256,928,4096,15872,65536,259584,1048576,4182016,16777216,
%T A220250 67051520,268435456,1073479680,4294967296,17178689536,68719476736,
%U A220250 274872664064,1099511627776,4398023442432,17592186044416,70368643514368
%N A220250 Sum of neighbor maps: number of nX2 binary arrays indicating the locations of corresponding elements equal to the sum mod 3 of their king-move neighbors in a random 0..2 nX2 array.
%C A220250 Column 2 of A220254
%H A220250 R. H. Hardin, <a href="/A220250/b220250.txt">Table of n, a(n) for n = 1..210</a>
%F A220250 Empirical: a(n)=4*a(n-1)+8*a(n-2)-32*a(n-3)-16*a(n-4)+64*a(n-5)
%F A220250 a(n) = 4^n - 2^(n-2)*(n+1)*(1-(-1)^n). - _Vaclav Kotesovec_, Jul 06 2013
%e A220250 Some solutions for n=3
%e A220250 ..0..0....1..1....1..1....1..0....0..1....0..0....0..1....1..0....0..1....0..0
%e A220250 ..0..1....0..1....0..0....0..0....1..1....0..0....0..0....0..0....0..1....0..1
%e A220250 ..0..0....1..1....0..0....0..1....1..0....1..0....0..0....1..0....0..1....1..0
%K A220250 nonn
%O A220250 1,1
%A A220250 _R. H. Hardin_ Dec 08 2012