A226401 - OEIS

%I #7 Mar 23 2024 17:30:29

%S 2,48,146,448,912,1646,2812,4564,6826,9996,14208,19364,26146,34488,

%T 44090,56418,71092,87614,107854,131136,156880,187906,223218,261362,

%U 305902,356414,410362,472988,542558,615414,700038,792754,890046,1001146,1120332

%N Number of nondecreasing -n..n vectors of length 4 whose dot product with some nonincreasing -n..n vector equals 4.

%C Row 4 of A226398.

%H R. H. Hardin, <a href="/A226401/b226401.txt">Table of n, a(n) for n = 1..45</a>

%e Some solutions for n=3:

%e   -2  -2  -3  -1  -3  -2  -3   0  -2  -2  -2  -3  -3  -1  -3   2

%e    1  -2  -1  -1  -3  -2  -3   1  -2   0   0  -2  -3   0  -3   2

%e    2   3   0  -1  -2  -2   0   1  -1   1   3  -2  -2   2  -1   3

%e    3   3   0  -1  -2   3   1   1   3   3   3   2  -1   3   3   3

%K nonn

%O 1,1

%A _R. H. Hardin_, Jun 06 2013