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Number of strings of numbers x(i=1..n) in 0..3 with sum i*x(i)^2 equal to n*9
1

%I #5 Mar 31 2012 12:35:59

%S 1,1,2,5,19,51,130,359,946,2333,5818,14088,33135,76611,173464,384457,

%T 837012,1790715,3766901,7802712,15923697,32039816,63611885,124689752,

%U 241431996,462031599,874300348,1636607223,3031814449,5560277156

%N Number of strings of numbers x(i=1..n) in 0..3 with sum i*x(i)^2 equal to n*9

%C Column 3 of A184441

%H R. H. Hardin, <a href="/A184435/b184435.txt">Table of n, a(n) for n = 1..149</a>

%e Some solutions for n=5

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

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

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

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

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

%K nonn

%O 1,3

%A _R. H. Hardin_ Jan 14 2011