171245domain: NAppears in sequencesNumber of binary words of length n in which the ones occur only in blocks of length at least 4.at n=30A005253Number of compositions of 5*n-3 into parts 2 and 5.at n=12A369843Expansion of (1 + x)/(1 - x^2*(1 + x)^3).at n=20A375315