1227133512domain: NAppears in sequencesNumber of integers from 1 to 10^(n+1)-1 that lack 0 and 1 as a digit.at n=9A052379Expansion of x*(1+3*x-4*x^2-5*x^3-4*x^6+4*x^5+3*x^4) / ((1+4*x^2)*(1+x^2)*(1-x^2+x^4)).at n=30A112523a(n) = Sum_{k=1..10} n^k.at n=8A228294