cp's OEIS Frontend

A222936 Sum of neighbor maps: number of 2Xn binary arrays indicating the locations of corresponding elements equal to the sum mod 4 of their horizontal and antidiagonal neighbors in a random 0..3 2Xn array.

%I A222936 #6 Jul 23 2025 03:17:45
%S A222936 4,16,48,256,1024,4096,15820,65536,262144,1048576,4182016,16777216,
%T A222936 67108864,268435456,1073476576,4294967296,17179869184,68719476736,
%U A222936 274872664064,1099511627776,4398046511104,17592186044416,70368643424320
%N A222936 Sum of neighbor maps: number of 2Xn binary arrays indicating the locations of corresponding elements equal to the sum mod 4 of their horizontal and antidiagonal neighbors in a random 0..3 2Xn array.
%C A222936 Row 2 of A222935
%H A222936 R. H. Hardin, <a href="/A222936/b222936.txt">Table of n, a(n) for n = 1..210</a>
%F A222936 Empirical: a(n) = 4*a(n-1) +32*a(n-4) -128*a(n-5) -212*a(n-8) +848*a(n-9) -1408*a(n-12) +5632*a(n-13) +10576*a(n-16) -42304*a(n-17) +22016*a(n-20) -88064*a(n-21) -171456*a(n-24) +685824*a(n-25) -149504*a(n-28) +598016*a(n-29) +1181696*a(n-32) -4726784*a(n-33) +458752*a(n-36) -1835008*a(n-37) -3653632*a(n-40) +14614528*a(n-41) -524288*a(n-44) +2097152*a(n-45) +4194304*a(n-48) -16777216*a(n-49)
%e A222936 Some solutions for n=3
%e A222936 ..1..0..0....0..1..1....1..0..1....0..0..0....0..0..0....0..0..1....0..0..1
%e A222936 ..1..1..0....1..0..0....0..0..0....0..1..0....1..0..1....0..1..1....1..1..0
%K A222936 nonn
%O A222936 1,1
%A A222936 _R. H. Hardin_ Mar 09 2013