

A203621


Highly antiimperfect numbers: n sets a record for the value of sigma*(n)n, where sigma*(n) is the sum of the antidivisors of n.


1



1, 2, 7, 10, 13, 17, 22, 27, 28, 32, 38, 45, 52, 60, 63, 67, 77, 95, 105, 130, 137, 143, 157, 158, 175, 193, 203, 247, 297, 315, 357, 423, 462, 472, 473, 578, 675, 682, 742, 770, 787, 1012, 1138, 1215, 1417, 1463, 1732, 1957, 2047, 2048, 2327, 2363, 2632
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OFFSET

1,2


COMMENTS

Antiimperfect numbers are antideficient numbers or antiabundant numbers.


REFERENCES

n=1. Antidivisors: 0. 01=1
n=2. Antidivisors: 0. 02=2
n=3. Antidivisors: 2. 23=1 less than 2: 3 is not in the sequence.
n=4. Antidivisors: 3. 34=1 less than 2: 4 is not in the sequence.
n=5. Antidivisors: 2,3. 53=2 equal to the maximum: 5 is not in the sequence.
n=6. Antidivisors: 4. 46=2 equal to the maximum: 6 is not in the sequence.
n=7. Antidivisors: 2,3,5. 107=3 new maximum: 7 is in the sequence.


LINKS

Paolo P. Lava, Table of n, a(n) for n = 1..100


MAPLE

P:=proc(i)
local a, k, n, s;
s:=0;
for n from 1 to i do
a:=0;
for k from 2 to n1 do if abs((n mod k) k/2)<1 then a:=a+k; fi; od;
if abs(na)>s then s:=abs(na); print(n); fi;
od;
end:
P(3000);


CROSSREFS

Cf. A066417, A074918, A192267, A192268.
Sequence in context: A277551 A029904 A026364 * A297832 A003158 A130336
Adjacent sequences: A203618 A203619 A203620 * A203622 A203623 A203624


KEYWORD

nonn


AUTHOR

Paolo P. Lava, Jan 04 2012


STATUS

approved



