5953572domain: NAppears in sequencesTetranacci numbers: a(n) = a(n-1) + a(n-2) + a(n-3) + a(n-4), with a(0)=a(1)=0, a(2)=1, a(3)=2.at n=26A001630Number of palindromic binary strings of length n having no 4-runs of 1's.at n=48A382478