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A140089
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Products of two triangular numbers each > 1.
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2
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9, 18, 30, 36, 45, 60, 63, 84, 90, 100, 108, 126, 135, 150, 165, 168, 198, 210, 216, 225, 234, 270, 273, 280, 315, 330, 360, 396, 408, 420, 441, 450, 459, 468, 513, 540, 546, 550, 570, 588, 630, 660, 675, 693, 720, 756, 759, 780, 784, 816, 825, 828, 900, 910
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OFFSET
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1,1
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LINKS
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MAPLE
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isA140089 := proc(n)
for d in numtheory[divisors](n) minus {1} do
if d^2 > n then
return false;
end if;
if isA000217(d) then
if isA000217(n/d) then
return true;
end if;
end if;
end do:
return false;
end proc:
for n from 1 to 1000 do
if isA140089(n) then
printf("%d, ", n) ;
end if;
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CROSSREFS
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KEYWORD
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nonn,changed
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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