3378240
domain: N
Appears in sequences
- Let S(n)=sigma(|n|)/2-n; sequence gives numbers n such that S(S(S(S(n))))=n. May be called {1,2}-sociable number of orders 1 or 2 or 4.at n=10A114529
- Numbers n such that there exists an x!=n that makes {n,n,x,x} an amicable multiset.at n=3A259306
- E.g.f. satisfies A(x) = 1 - x^2*log(1 - x*A(x)^2).at n=9A371233