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A203695
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Vandermonde sequence using x^2 + y^2 applied to the first n triangular numbers: 1,3,6,10,...,n(n+1)/2.
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3
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OFFSET
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1,2
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COMMENTS
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See A093883 for a discussion and guide to related sequences.
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LINKS
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MATHEMATICA
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f[j_] := j (j + 1)/2; z = 11;
u[n_] := Product[f[j]^2 + f[k]^2, {j, 1, k - 1}]
v[n_] := Product[u[n], {k, 2, n}]
Table[v[n], {n, 1, z}] (* A203695 *)
Table[v[n + 1]/v[n], {n, 1, z}] (* A203696 *)
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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STATUS
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approved
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