OFFSET
1,1
COMMENTS
For any number x we consider the sum of its anti-divisors which are coprime to x (unitary anti-divisors). The sequence list the numbers for which this sum is equal to x.
Subset of A192270.
I found only 2 unitary anti-amicable numbers: 18208, 20470.
No other terms < 2147000000. Jud McCranie, Sep 21 2019.
EXAMPLE
Anti-divisors of 1066 are 3, 4, 9, 27, 52, 79, 164, 237, 711. The anti-divisors which are coprime to 1066 are 3, 9, 27, 79, 237, 711 and their sum is 3 + 9 + 27 + 79 + 237 + 711 = 1066.
MAPLE
P:=proc(q) local a, k, n;
for n from 3 to q do a:=0; b:=0;
for k from 2 to n-1 do if abs((n mod k)-k/2)<1 then
if gcd(n, k)=1 then a:=a+k; fi; fi; od;
if n=a then print(n); fi; od; end: P(10^6);
CROSSREFS
KEYWORD
nonn,more
AUTHOR
Paolo P. Lava, Aug 05 2014
EXTENSIONS
a(14)-a(23) by Jud McCranie, Sep 21 2019.
STATUS
approved