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A212926 Number of n X 4 0..3 arrays with no column j greater than column j-1 in all rows.

%I A212926 #13 Jul 04 2025 19:20:55
%S A212926 35,39695,14177855,4041974015,1075113010175,279128913678335,
%T A212926 71832238695530495,18425105216039878655,4720288982579567394815,
%U A212926 1208726373482189187710975,309465862773085401709019135
%N A212926 Number of n X 4 0..3 arrays with no column j greater than column j-1 in all rows.
%H A212926 R. H. Hardin, <a href="/A212926/b212926.txt">Table of n, a(n) for n = 1..210</a>
%F A212926 Empirical: a(n) = 405*a(n-1) -43860*a(n-2) +1524160*a(n-3) -15636480*a(n-4) +14155776*a(n-5).
%F A212926 Empirical: a(n) = -3*96^n+256^n+36^n-1+2*16^n. - _R. J. Mathar_, Jun 27 2012
%e A212926 Some solutions for n=3
%e A212926 ..3..1..1..1....0..1..1..3....1..0..2..3....2..0..3..0....1..3..2..2
%e A212926 ..3..3..3..1....3..0..3..1....2..1..1..0....0..2..1..1....0..2..2..1
%e A212926 ..3..1..3..3....1..3..2..1....3..3..0..1....0..2..1..0....1..0..1..1
%Y A212926 Column 4 of A212930.
%K A212926 nonn
%O A212926 1,1
%A A212926 _R. H. Hardin_, May 31 2012