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A332047 Numbers that are not distended, but all sums of subsets of divisors are distinct. 1
175, 442, 575, 638, 782, 806, 874, 875, 986, 1178, 1209, 1334, 1394, 1426, 1462, 1479, 1573, 1598, 1615, 1634, 1702, 1767, 1786, 1833, 1886, 2001, 2014, 2091, 2125, 2146, 2193, 2255, 2261, 2294, 2303, 2378, 2387, 2431, 2438, 2451, 2542, 2553, 2585, 2597, 2666, 2679, 2714, 2717, 2726, 2755, 2806 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
LINKS
EXAMPLE
a(3) = 575 has divisors 1, 5, 23, 25, 115, 575. It is not distended because 1+5+23 >= 25, but the sums of all 2^6 subsets of divisors are distinct, so 575 is in the sequence.
MAPLE
filter:= proc(n) local d, sd, S, T, v;
d:= sort(convert(numtheory:-divisors(n), list));
sd:= ListTools:-PartialSums(d);
if min(d[2..-1]-sd[1..-2])> 0 then return false fi;
S:= {};
T:= combinat:-subsets(d);
while not T[finished] do
v:= convert(T[nextvalue](), `+`);
if member(v, S) then return false fi;
S:= S union {v};
od;
true
end proc:
select(filter, [$1..3000]);
CROSSREFS
Sequence in context: A351720 A015806 A109836 * A186211 A205748 A352109
KEYWORD
nonn
AUTHOR
Robert Israel, Feb 06 2020
STATUS
approved

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Last modified February 25 04:28 EST 2024. Contains 370309 sequences. (Running on oeis4.)