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A223728
Multiplicities for A223727: primitive sums of four distinct nonzero squares.
2
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 3, 1, 1, 1, 1, 1, 1, 2, 1, 1, 2, 2, 1, 2, 3, 2, 1, 1, 1, 3, 2, 1, 3, 1, 1, 1, 2, 1, 1, 2, 1, 5, 1, 2, 3, 1, 1, 2, 3, 1, 2, 1, 1, 2, 4, 2, 1, 2, 3, 1, 5, 2, 2, 2, 2, 2, 4, 3, 1, 4, 1, 1, 4, 2, 2, 2, 5, 3, 1, 6, 3, 3, 1, 2, 1, 1, 4, 4, 2, 5, 1, 3, 7, 3, 2
OFFSET
1,16
COMMENTS
A223728(n) has a(n) different primitive representations as sum of four distinct nonzero squares, n>=1.
FORMULA
a(n) = k if there are k different solutions for A223728(n) = sum(s(j)^2, j=1..4), with 0 < s(1) < s(2) < s(3) < s(4) and gcd(s(1),s(2),s(3),s(4)) = 1.
EXAMPLE
a(16) = 3 because A223727(16) = 78 has three s-quadruples, namely [1, 2, 3, 8], [1, 4, 5, 6] and [2, 3, 4, 7].
a(23) = 2 from A223727(23) = 90 with s-quadruples [1, 2, 6, 7] and [1, 3, 4, 8].
CROSSREFS
Sequence in context: A031243 A030394 A223726 * A030596 A031277 A001165
KEYWORD
nonn
AUTHOR
Wolfdieter Lang, Mar 27 2013
STATUS
approved