- "Max B" asked

> What would

The "excluding" is unnecessary, since

> "n such that the sum of divisors of

> n = sum of the anti-divisors of n

> excluding 1)" be?

1 is not an anti-divisor.

For what it's worth, I reckon that

the sequence, up to 10^5, is

11

22

33

65

82

117

218

483

508

537

6430

21541

Good bye! - Off-list, Max B asked for my code for this exercise.

For what it's worth, this was it:

{SA(n)=local(o);o=n;while(o%2==0,o=o/2);

sigma(2*n+1,1)+sigma(2*n-1,1)+sigma(o,1)*2*n/o-6*n-2}

for(n=1,10^5,if(sigma(n,1)==SA(n),print(n)))

But I did no sanity check!

David