78576

Appears in sequences

• Numbers k such that 8*10^k + R_k is prime, where R_k = 11...1 is the repunit (A002275) of length k.at n=13A056722
• Triangle read by rows: T(n,k) = number of peakless Motzkin paths of length n containing k U H^j Us for some j>0, where U=(1,1) and H=(1,0) (can be easily expressed using RNA secondary structure terminology).at n=50A097777
• Number of reduced words of length n in Coxeter group on 4 generators S_i with relations (S_i)^2 = (S_i S_j)^8 = I.at n=10A164697
• Number of ways to place 2 nonattacking zebras on an n X n board.at n=19A172137