248749

Properties

Appears in sequences

• a(n) = (2n)! * Sum_{k=0..n} (-1)^k * binomial(n,k) / (n+k)!.at n=6A006902
• Array read by antidiagonals upwards: h(n,k) = number of sequences with n copies each of 1,2,...,k and longest increasing subsequence of length k (n>=1, k>=1).at n=26A047909
• Number T(n,k) of words on {1,1,2,2,...,n,n} with longest increasing subsequence of length k; triangle T(n,k), n>=0, 0<=k<=n, read by rows.at n=27A267480
• Number of sequences with n copies each of 1,2,...,6 and longest increasing subsequence of length 6.at n=1A268842
• Prime numbers p such that the set of composite numbers in the range [p+1, nextprime(p)-1] has more than one element and all the elements have the same number of divisors.at n=28A332740
• Primes of the form 398*x^2-1.at n=18A338476
• Table read by rows. A statistic of permutations of the multiset {1,1,2,2,...,n,n}.at n=15A358112
• a(n) is the least odd prime not in A001359 such that all subsequent composites in the gap up to the next prime have exactly n prime factors, counted with multiplicity.at n=3A359638
• Prime numbersat n=21942