290237644domain: NAppears in sequencesa(n) = Sum_{i=0..2*n} Sum_{j=0..n-1} A026519(j, i).at n=21A026534The base 6 numbers 4 44 444 4444 44444 ... converted to base 10.at n=10A125687The "Fouriest" numbers: numbers that can be expressed as a string of 4's longer than the original number in some base.at n=22A349031