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A224306 Number of nX4 0..2 arrays with diagonals and rows unimodal and antidiagonals nondecreasing.

%I A224306 #6 Jul 23 2025 05:05:15
%S A224306 46,698,5996,45453,345875,2717759,22071219,182843194,1528645389,
%T A224306 12825738594,107715455487,904773390455,7599493889175,63827735783412,
%U A224306 536075684379248,4502373101398007,37814478865105363,317596919801312214
%N A224306 Number of nX4 0..2 arrays with diagonals and rows unimodal and antidiagonals nondecreasing.
%C A224306 Column 4 of A224310
%H A224306 R. H. Hardin, <a href="/A224306/b224306.txt">Table of n, a(n) for n = 1..210</a>
%F A224306 Empirical: a(n) = 15*a(n-1) -58*a(n-2) -13*a(n-3) +160*a(n-4) +1879*a(n-5) -7373*a(n-6) +6407*a(n-7) -2233*a(n-8) +11269*a(n-9) -128277*a(n-10) +514460*a(n-11) -559176*a(n-12) +774916*a(n-13) +91024*a(n-14) -426367*a(n-15) -1572540*a(n-16) -2736461*a(n-17) -3322156*a(n-18) -10388293*a(n-19) +187424*a(n-20) -4090338*a(n-21) +4202406*a(n-22) +9112758*a(n-23) +21520552*a(n-24) +26916252*a(n-25) +22991028*a(n-26) +42071688*a(n-27) +28540632*a(n-28) +18156960*a(n-29) +483840*a(n-30) for n>35
%e A224306 Some solutions for n=3
%e A224306 ..0..0..0..0....0..1..1..1....2..2..0..0....1..1..1..0....0..0..0..2
%e A224306 ..0..0..0..1....1..2..2..2....2..2..1..0....1..2..1..1....0..0..2..2
%e A224306 ..0..0..2..2....2..2..2..1....2..2..0..0....2..2..1..0....1..2..2..1
%K A224306 nonn
%O A224306 1,1
%A A224306 _R. H. Hardin_ Apr 03 2013