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A323334
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Sum of distinct products i*j*k with 1 <= i, j, k <= n.
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2
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1, 15, 90, 310, 990, 2220, 5300, 9660, 17130, 28670, 52848, 75696, 128541, 183393, 257628, 344316, 529038, 683316, 1001110, 1256010, 1607004, 2049490, 2837700, 3330636, 4177186, 5150340, 6273810, 7432702, 9779991, 11124711, 14381168, 16610640, 19542393, 23032799, 26873769
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OFFSET
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1,2
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LINKS
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EXAMPLE
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a(2) = 1 + 2 + 4 + 8 = 15.
a(3) = 1 + 2 + 3 + 4 + 6 + 8 + 9 + 12 + 18 + 27 = 90.
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MATHEMATICA
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a[n_] := Table[i j k, {i, n}, {j, n}, {k, n}] // Flatten // Union // Total;
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PROG
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(Python)
def aupton(terms):
alst, s, pset = [], 0, set()
for n in range(1, terms):
for i in range(1, n+1):
for j in range(i, n+1):
p = i*j*n # k = n
if p not in pset:
pset.add(p)
s += p
alst.append(s)
return alst
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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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