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 A248836 Number of length n arrays x(i), i=1..n with x(i) in 0..i and no value appearing more than 2 times 2

%I

%S 2,6,22,96,482,2736,17302,120576,917762,7574016,67354582,642041856,

%T 6530291042,70589700096,808090395862,9766250151936,124258689304322,

%U 1660195646078976,23239748527125142,340125128186658816

%N Number of length n arrays x(i), i=1..n with x(i) in 0..i and no value appearing more than 2 times

%C Column 2 of A248842

%H R. H. Hardin, <a href="/A248836/b248836.txt">Table of n, a(n) for n = 1..210</a>

%e Some solutions for n=6

%e ..1....1....1....1....1....0....1....0....0....0....1....0....1....1....1....0

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

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

%e ..1....4....0....0....4....2....0....3....3....2....3....3....4....0....0....2

%e ..4....0....3....4....3....4....4....0....1....5....4....2....2....2....2....4

%e ..5....6....4....5....4....0....3....6....6....5....0....2....5....4....4....4

%K nonn

%O 1,1

%A _R. H. Hardin_, Oct 15 2014

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Last modified November 30 09:21 EST 2022. Contains 358438 sequences. (Running on oeis4.)