256410

Appears in sequences

• a(n) = least k such that 2ik + 1 is prime for all 1 <= i <= n.at n=6A071576
• a(n) = least k such that 2ik + 1 is prime for all 1 <= i <= n.at n=7A071576
• Numbers k such that 2k+1, 4k+1, 6k+1, 8k+1 and 10k+1 are primes.at n=17A124410
• Numbers k such that 2k+1, 4k+1, 6k+1, 8k+1, 10k+1 and 12k+1 are primes.at n=3A124411
• Numbers k such that 2*k+1, 4*k+1, 8*k+1, 16*k+1 and 32*k+1 are primes.at n=31A124413
• A convolution triangle of numbers obtained from A036224.at n=32A132166
• The number of ways of putting n labeled items into k labeled boxes so that each box receives at least 3 objects.at n=20A200092
• Number of 2 X 2 matrices with all elements in {0,1,...,n} and nonnegative even determinant.at n=29A210371
• a(n) = (n!)^2 * Sum_{k=0..floor(n/2)} 1 / ((n-2*k)! * 4^k * k!).at n=7A346224
• a(n) = Sum_{k=0..floor(n/3)} binomial(3*n-8*k,k).at n=23A373640