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A226445
Smallest k such that n is the n-th largest anti-divisor of k.
1
5, 10, 18, 32, 45, 94, 220, 175, 325, 247, 630, 578, 637, 1012, 2712, 3867, 4851, 2993, 10230, 2363, 6435
OFFSET
2,1
EXAMPLE
a(7) = 94 because the sorted anti-divisors of 94 are (63, 38, 27, 21, 10, 9, 7, 3, 2) and 7 is the 7th anti-divisor.
MAPLE
antidivisors := proc(n)
local a, k;
a := {} ;
for k from 2 to n-1 do
if abs((n mod k)- k/2) < 1 then
a := a union {k} ;
end if;
end do:
convert(a, list) ;
end proc:
A226445 := proc(n)
local k, adv;
for k from 3 do
adv := sort(antidivisors(k)) ;
if nops(adv) >= n then
if op(-n, adv) = n then
return k;
end if;
end if;
end do:
end proc: # R. J. Mathar, Jun 18 2013
CROSSREFS
Sequence in context: A025010 A299144 A058555 * A296552 A251928 A153370
KEYWORD
nonn,less
AUTHOR
STATUS
approved