24666

Appears in sequences

• a(n) = n! times probability that an ordered pair of elements of S_n chosen at random (with replacement) generate S_n.at n=5A040175
• Convolution of large Schroeder numbers and central binomial coefficients.at n=7A110276
• a(n) counts the distinct cubical (on alphabet of 3 symbols) billiard words with length n, acting as prefix to just k = 2 such words of length n+1 (that is, a subset of "special").at n=18A180438
• Number of (n+2)X(6+2) 0..3 arrays with every 3X3 subblock row and diagonal sum equal to 0 2 5 6 or 7 and every 3X3 column and antidiagonal sum not equal to 0 2 5 6 or 7.at n=2A252677
• T(n,k)=Number of (n+2)X(k+2) 0..3 arrays with every 3X3 subblock row and diagonal sum equal to 0 2 5 6 or 7 and every 3X3 column and antidiagonal sum not equal to 0 2 5 6 or 7.at n=30A252679
• Number of (3+2)X(n+2) 0..3 arrays with every 3X3 subblock row and diagonal sum equal to 0 2 5 6 or 7 and every 3X3 column and antidiagonal sum not equal to 0 2 5 6 or 7.at n=5A252682
• Integers m such that iterating the map f(x) = x^2 + 1 on m generates a number ending with m in binary format.at n=15A354832
• a(1) = 1, a(2) = 2; for n >= 3, a(n) = (n-1)^3 - a(n-1) - a(n-2).at n=41A361134
• Irregular triangle read by rows: T(n,k) is the number of n X n binary matrices containing k South-East paths of 1's connecting the top left and bottom right corners.at n=41A380392