25227

Appears in sequences

• Kekulé numbers for certain benzenoids.at n=4A110691
• Number of isomorphism classes of connected 4-regular loopless multigraphs of order n.at n=11A129417
• Number of distinct solutions of sum{i=1..3}(x(2i-1)*x(2i)) = 1 (mod n), with x() only in 1..n-1.at n=16A180785
• Number of 0..1 arrays x(0..n-1) of n elements with each no smaller than the sum of its four previous neighbors modulo 2.at n=26A200462
• Number of (n+2)X(2+2) 0..2 arrays with every consecutive three elements in every row having 2 or 3 distinct values, in every column 1 or 2 distinct values, in every diagonal 2 distinct values, and in every antidiagonal 2 distinct values, and new values 0 upwards introduced in row major order.at n=1A252878
• T(n,k)=Number of (n+2)X(k+2) 0..2 arrays with every consecutive three elements in every row having 2 or 3 distinct values, in every column 1 or 2 distinct values, in every diagonal 2 distinct values, and in every antidiagonal 2 distinct values, and new values 0 upwards introduced in row major order.at n=4A252882
• Number of (2+2)X(n+2) 0..2 arrays with every consecutive three elements in every row having 2 or 3 distinct values, in every column 1 or 2 distinct values, in every diagonal 2 distinct values, and in every antidiagonal 2 distinct values, and new values 0 upwards introduced in row major order.at n=1A252884
• Array read by antidiagonals: T(n,r) is the number of connected r-regular loopless multigraphs on n unlabeled nodes.at n=131A328682
• Numbers k such that the sums (with multiplicity) of prime factors of k and k+1 are both squares.at n=25A359445