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Number of nondecreasing arrays of n 0..n-1 integers with the sum of their 2nd powers equal to sum(i^2,i=0..n-1)
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%I #5 Sep 11 2012 05:31:32

%S 1,1,1,1,2,4,14,37,105,309,939,2903,8865,28163,90648,297615,989077,

%T 3320885,11280835,38583017,133018026,461630411,1612842357,5667628973,

%U 20019876401,71078302590,253504107762,908014000543,3265037780657

%N Number of nondecreasing arrays of n 0..n-1 integers with the sum of their 2nd powers equal to sum(i^2,i=0..n-1)

%C Column 2 of A216635

%H R. H. Hardin, <a href="/A216630/b216630.txt">Table of n, a(n) for n = 1..49</a>

%e All solutions for n=6

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

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

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

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

%e ..4....5....4....3

%e ..5....5....4....5

%K nonn

%O 1,5

%A _R. H. Hardin_ Sep 11 2012