312000

Appears in sequences

• Maximum number of odd 2 X 2 submatrices over all 2n X 2n (0,1) matrices.at n=19A093699
• Number of ways to arrange the numbers (1,3,5,7,9,...,2n-1) in a circle such that every two adjacent numbers are relatively prime.at n=10A107763
• Number of permutations of (the positive integers <= n and coprime to n), where each element of the permutations is coprime to its adjacent elements.at n=21A109813
• Number of 0..n arrays x(0..3) of 4 elements with each no smaller than the sum of its previous elements modulo (n+1).at n=37A200253
• Values of the difference d for 7 primes in arithmetic progression with the minimal start sequence {7 + j*d}, j = 0 to 6.at n=17A206041
• Łukasiewicz words (without the last zero) for rooted plane trees where non-leaf branching can occur only at the leftmost branch of any level, but nowhere else.at n=42A209644
• Number of (w,x,y,z) with all terms in {1,...,n} and w<2x and y>=3z.at n=40A212511
• Number of invertible octonions over Z/nZ.at n=4A239441
• Numbers k such that k divides the number of overpartitions of k (A015128).at n=41A299961
• G.f. A(x) satisfies: 1 - x = Sum_{n>=0} x^n * (x^(2*n) + (-1)^n*A(x))^n.at n=20A352817