# Greetings from The On-Line Encyclopedia of Integer Sequences! http://oeis.org/

Search: id:a198536
Showing 1-1 of 1

%I A198536 #15 Jan 20 2024 17:46:48
%S A198536 404,7937268,163506788110,3368739754955320,69406373651979823710,
%T A198536 1429984226143212404754264,29462062047551694076888833310,
%U A198536 607008863611669902737169765762040
%N A198536 Number of 2n X 4 0..4 arrays with values 0..4 introduced in row major order and each element equal to an even number of horizontal and vertical neighbors.
%C A198536 Column 2 of A198538.
%H A198536 R. H. Hardin, <a href="/A198536/b198536.txt">Table of n, a(n) for n = 1..142</a>
%F A198536 Empirical: a(n) = 21092*a(n-1) -10151677*a(n-2) +1615488592*a(n-3) -100012996587*a(n-4) +3657934987820*a(n-5) -199109856057719*a(n-6) +11035156399508768*a(n-7) -386864139175024800*a(n-8) +4074211331329931264*a(n-9) +27502847510918746368*a(n-10) -584633432058829185024*a(n-11) +155716589412424286208*a(n-12) +27704839078255785934848*a(n-13) -67555504034237340712960*a(n-14) -521383121388940359106560*a(n-15) +2165438441332855701241856*a(n-16) +1920671303369098918887424*a(n-17) -21445602402910633696690176*a(n-18) +32886302391654339326246912*a(n-19) +4723519404374252060672*a(n-20) -34312714864530842122715136*a(n-21) +19342813113834066795298816*a(n-22).
%e A198536 Some solutions for n=3
%e A198536 ..0..0..0..0....0..0..0..0....0..0..0..0....0..0..0..0....0..0..0..0
%e A198536 ..0..1..2..0....0..1..2..0....0..1..2..0....0..1..2..0....0..1..2..0
%e A198536 ..0..0..0..0....0..0..0..0....0..0..0..0....0..0..0..0....0..0..0..0
%e A198536 ..3..4..2..3....2..3..2..3....3..4..2..2....2..3..2..3....2..3..2..3
%e A198536 ..2..0..3..4....3..2..3..4....4..3..2..2....4..0..1..0....3..4..1..2
%e A198536 ..3..2..1..3....2..1..4..2....0..1..3..0....3..2..0..3....1..3..4..0
%Y A198536 Cf. A198538.
%K A198536 nonn,more
%O A198536 1,1
%A A198536 _R. H. Hardin_, Oct 26 2011

# Content is available under The OEIS End-User License Agreement: http://oeis.org/LICENSE