%I #5 Nov 22 2016 06:51:17

%S 6,100,1609,19624,178352,1287838,7795151,41058743,193149285,826734193,

%T 3264405727,12016477160,41579224479,136142690453,424140541353,

%U 1263030700894,3609095743983,9929303441355,26377932553959,67838309686132

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

%C Column 2 of A278435.

%H R. H. Hardin, <a href="/A278430/b278430.txt">Table of n, a(n) for n = 1..210</a>

%H R. H. Hardin, <a href="/A278430/a278430.txt">Empirical polynomial of degree 31</a>

%F Empirical polynomial of degree 31 (see link above)

%e Some solutions for n=4

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

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

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

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

%Y Cf. A278435.

%K nonn

%O 1,1

%A _R. H. Hardin_, Nov 22 2016