45366domain: NAppears in sequencesNested floor product of n and fractions (k+1)/k for all k>0 (mod 5), divided by 5.at n=21A073362a(0)=1. a(n) = a(n-1)*(n+1), if n is in the sequence. a(n)= a(n-1) +1, if n is missing from the sequence.at n=15A118471a(n) = n! + (n-1)! + n-2.at n=7A341302