18084

Appears in sequences

• Number of ordered quadruples of integers from [ 1,n ] with no common factors between pairs.at n=42A015636
• Number of partitions of floor(n^2/2) with at most n parts and maximal height n.at n=11A029895
• Numbers k such that 217*2^k+1 is prime.at n=6A032485
• Denominators of continued fraction convergents to sqrt(349).at n=7A041661
• Parker's partition triangle T(n,k) read by rows (n >= 1 and 0 <= k <= n-1).at n=60A047812
• Central elements in Parker's partition triangle.at n=5A051643
• Number of directed aggregates of height <= 2 with n cells.at n=11A082397
• a(n) = (5*n+2)*(5*n+7).at n=26A085036
• Diagonal sums of number triangle A109974.at n=15A109976
• Numbers n such that the numerator of Sum_{i=1..n} (1/i^2), in reduced form, is prime.at n=32A111354
• Transpose T(n,k) of Parker's partition triangle A047812 (n >= 1 and 0 <= k <= n-1).at n=60A136621
• Number of subsets of {1, 2, ..., n} containing n and having <=5 pairwise coprime elements.at n=42A186989
• Molecular topological indices of the cycle graphs.at n=32A192797
• Numbers n such that sigma(n) is a Fibonacci number.at n=10A272412
• Maximal coefficient among the polynomials in row n of the triangle of q-binomial coefficients.at n=22A277218
• Number of nX3 0..1 arrays with every element unequal to 0, 1, 3 or 5 king-move adjacent elements, with upper left element zero.at n=13A303964
• a(n) = Sum_{i=1..floor((n-1)/2)} i * (n-i)^2.at n=23A308038
• Numbers whose divisors can be partitioned into two disjoint sets whose sums are consecutive Fibonacci numbers.at n=4A333677
• a(n) = (prime(n)+1) * prime(n+1).at n=31A345727