240240

Appears in sequences

• a(n) = (2n+4)!/(4!*n!*(n+1)!).at n=6A002803
• Numbers k such that sigma(k)/phi(k) sets a new record.at n=26A018894
• Denominators of poly-Bernoulli numbers B_n^(k) with k=3.at n=15A027646
• a(n) = 7*(n+1)*binomial(n+5,7).at n=7A027812
• a(n) = 66*(n+1)*binomial(n+5,11).at n=3A027816
• Number of reversible strings with n-1 beads of 2 colors. 7 beads are black. String is not palindromic.at n=17A032094
• a(n) = (n+9)!/9!.at n=5A049398
• Product of 5 consecutive integers.at n=14A052787
• E.g.f.: x^5*exp(x)-x^5.at n=14A052800
• Number of (2,2; n,n)-partitions of a chain of length n^2 + n.at n=5A055660
• Write the integers in groups: 0; 1,2; 3,4,5; 6,7,8,9; ... and form the product of the members of each group.at n=4A056923
• Number of ways to place 3 nonattacking kings on an n X n board.at n=11A061996
• Numbers k such that sigma(k) - usigma(k) is a square and sets a new record for such squares.at n=37A063840
• Denominators of partial sums of reciprocals of A051451 (A051451 includes lcm(1,...,x), x=power of prime from A000961 and also contains 1).at n=10A064889
• Denominator of Sum_{k=1..n} d(k)/k, where d() = A000005().at n=15A065080
• Triangle T(n,r), n>=0, r=n, n-1, ..., 1, 0; where T(n,r) = product of all possible sums of r numbers chosen from [1..n].at n=16A067050
• a(n) = lcm{1, ..., 2n} / binomial(2n, n).at n=16A068550
• Smallest product (n+1)(n+2)...(n+k) that is divisible by the product of all the primes up to n.at n=8A075366
• Integers n for which the ratio phi(n)/pi(n) is smaller than for any subsequent n. Here phi(n) is Euler's totient function and pi(n) is the number of primes that are at most n.at n=28A080289
• Generalized Stirling2 array (7,2).at n=21A091747