228614400
domain: N
Appears in sequences
- Sets record for f(n) = |{(a,b):a*b=n and a|b}|. Also squares of highly composite numbers A002182.at n=21A046952
- Expansion of e.g.f. 1/((1-2*x^2)*(1-x)).at n=10A052634
- a(n) = ((n-1)! * (n+1)!) / n.at n=7A179442
- a(n) = (n!/floor(n/2)!)^2.at n=9A193282
- Number of length n mixed-radix numbers with base [2, 3, 4, ...] (factorial base) such that the parities of adjacent digits differ.at n=14A219024
- Numbers with a record number of noninfinitary square divisors.at n=16A358263
- Number of permutations of [n] such that the minimal element of each cycle is also its length.at n=17A364406
- Smallest k for which the number of divisors d of k such that A000005(d) = A000005(k/d) is equal to n.at n=17A391603