A278548 - OEIS

%I #4 Nov 23 2016 07:54:33

%S 0,70,1531,25402,385040,4880813,50476458,435272199,3222371162,

%T 21002624643,122940347621,656384657007,3235421775340,14866063786408,

%U 64169850484506,261881056692205,1015819011059751,3761887253493383

%N Number of nX2 0..3 arrays with rows and columns in lexicographic nondecreasing order but with exactly two mistakes.

%C Column 2 of A278553.

%H R. H. Hardin, <a href="/A278548/b278548.txt">Table of n, a(n) for n = 1..210</a>

%H R. H. Hardin, <a href="/A278548/a278548.txt">Empirical polynomial of degree 47</a>

%F Empirical polynomial of degree 47 (see link above)

%e Some solutions for n=4

%e ..3..0. .3..0. .0..0. .0..1. .1..3. .1..3. .2..3. .2..1. .1..1. .2..2

%e ..3..2. .2..2. .2..2. .2..3. .3..3. .1..1. .3..1. .2..2. .2..1. .3..2

%e ..1..0. .3..1. .3..2. .2..1. .2..3. .3..3. .3..0. .2..3. .0..0. .0..3

%e ..1..2. .3..2. .2..2. .1..3. .0..2. .2..2. .1..3. .2..1. .2..3. .1..2

%Y Cf. A278553.

%K nonn

%O 1,2

%A _R. H. Hardin_, Nov 23 2016