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A132432
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Number of different values of i^2+j^2+k^2+l^2+m^2 for i,j,k,l,m in [0,n].
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3
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1, 6, 18, 38, 66, 99, 147, 201, 262, 332, 411, 498, 601, 702, 819, 946, 1078, 1221, 1375, 1533, 1703, 1882, 2076, 2264, 2479, 2691, 2922, 3159, 3403, 3655, 3924, 4193, 4478, 4770, 5071, 5376, 5705, 6032, 6372, 6719, 7081, 7448, 7828, 8214, 8616, 9017, 9438
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OFFSET
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0,2
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LINKS
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EXAMPLE
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a(3) = 18 because the 18 different sums of 5 squares of integers from 0 to 2 are: {20, 17, 16, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, 1, 0} by permutations of 2^2 + 2^2 + 2^2 + 2^2 + 2^2 = 20; 2^2 + 2^2 + 2^2 + 2^2 + 1^2 = 17; 2^2 + 2^2 + 2^2 + 2^2 + 0^2 = 16; 2^2 + 2^2 + 2^2 + 1^2 + 1^2 = 14; 2^2 + 2^2 + 2^2 + 1^2 + 0^2 = 13; 2^2 + 2^2 + 2^2 + 0^2 + 0^2 = 12; 2^2 + 2^2 + 1^2 + 1^2 + 1^2 = 11; 2^2 + 2^2 + 1^2 + 1^2 + 0^2 = 10; 2^2 + 2^2 + 1^2 + 0^2 + 0^2 = 9; 2^2 + 2^2 + 0^2 + 0^2 + 0^2 = 2^2 + 1^2 + 1^2 + 1^2 + 1^2 = 8; 2^2 + 1^2 + 1^2 + 1^2 + 0^2 = 7; 2^2 + 1^2 + 1^2 + 0^2 + 0^2 = 6; 2^2 + 1^2 + 0^2 + 0^2 + 0^2 = 1^2 + 1^2 + 1^2 + 1^2 + 1^2 = 5; 2^2 + 0^2 + 0^2 + 0^2 + 0^2 = 1^2 + 1^2 + 1^2 + 1^2 + 0^2 = 4; 1^2 + 1^2 + 1^2 + 0^2 + 0^2 = 3; 1^2 + 1^2 + 0^2 + 0^2 + 0^2 = 2; 1^2 + 0^2 + 0^2 + 0^2 + 0^2 = 1; 0^2 + 0^2 + 0^2 + 0^2 + 0^2 = 0.
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MAPLE
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S:= proc(k, n) option remember;
if k = 0 or n = 0 then {0} else
`union`(seq(map(`+`, procname(j, n-1), (k-j)*n^2), j=1..k-1),
{k*n^2}, procname(k, n-1)) fi end proc:
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MATHEMATICA
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Table[Length@ Union@Flatten@ Table[i^2 + j^2 + k^2 + l^2 + m^2, {i, 0, n}, {j, i, n}, {k, j, n}, {l, k, n}, {m, l, n}], {n, 0, 49}]
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CROSSREFS
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KEYWORD
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easy,nonn
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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