21926

Appears in sequences

• Number of binary words of length n containing at least one subword 10001 and no subwords 10^{i}1 with i<3.at n=31A143283
• Number of ways to arrange 3 nonattacking queens on the lower triangle of an n X n board.at n=11A194493
• a(0) = 0; a(n+1) = 2*a(n) + k where k = 0 if prime(n+2)/prime(n+1) < prime(n+1)/prime(n), otherwise k = 1.at n=15A215410
• Number of length 3 arrays x(i), i=1..3 with x(i) in i..i+n and no value appearing more than 2 times.at n=26A250352
• Number of (n+2) X (1+2) 0..1 arrays with no 3 x 3 subblock diagonal sum 1 and no antidiagonal sum 1 and no row sum 0 or 1 and no column sum 0 or 1.at n=8A255152
• T(n,k)=Number of (n+2)X(k+2) 0..1 arrays with no 3x3 subblock diagonal sum 1 and no antidiagonal sum 1 and no row sum 0 or 1 and no column sum 0 or 1.at n=36A255159
• Number of permutations of length n that avoid 4123, 1324, and 31524.at n=9A277222
• Number of ways to choose a set partition of a strict integer partition of n.at n=32A294617
• Number of nX6 0..1 arrays with every element unequal to 0, 1, 3, 4, 6 or 7 king-move adjacent elements, with upper left element zero.at n=6A306127
• Number of nX7 0..1 arrays with every element unequal to 0, 1, 3, 4, 6 or 7 king-move adjacent elements, with upper left element zero.at n=5A306128
• Number of self-inverse double cosets in D_n\S_n/D_n.at n=10A384631