1316904

Appears in sequences

• Number of nonempty subsets of {1,2,...,n} in which exactly 5/6 of the elements are <= (n-1)/2.at n=33A047181
• Number of nonempty subsets of {1,2,...,n} in which exactly 5/6 of the elements are <= (n-2)/2.at n=33A047192
• If f[x]=(sum of unitary-proper divisors of x)=A063919[x] is iterated, the iteration may lead to a fixed point which is either 0 or belongs to A002827, a unitary-perfect-number >1: 6,60,90,87360... Sequence gives initial values for which the iteration ends in 87360, the 4th unitary perfect number.at n=12A098186