6249740domain: NAppears in sequencesFrequency of the hexadecimal 8 in the first 10^n hexadecimal digits of Pi.at n=7A099341Number of -2..2 arrays x(i) of n+1 elements i=1..n+1 with set{t,u,v in 0,1}((x[i+t]+x[j+u]+x[k+v])*(-1)^(t+u+v)) having two, three, four or five distinct values for every i,j,k<=n.at n=18A211571