290304

Appears in sequences

• Expansion of e.g.f.: cos(arctanh(x)*log(x+1))=1-12/4!*x^4+60/5!*x^5-570/6!*x^6+3780/7!*x^7...at n=9A012702
• Numbers that can be written as k/d(k) in four or more ways, where d(k) = number of divisors of k.at n=31A051346
• a(n) = Product_{i=4..n} (prime(i) - 5).at n=8A059864
• E.g.f.: exp(-(x^5/5))/(1-x).at n=9A060725
• Numbers k such that k = phi(sigma(phi(sigma(phi(sigma(k)))))).at n=23A067884
• a(n) = n! / A003040(n).at n=12A082914
• Duplicate of A082914.at n=12A092031
• Numerators of the average length of a line segment picked at random in the unit n-ball for odd n.at n=4A093530
• Hook products of all partitions of 13.at n=0A093792
• Hook products of all partitions of 13.at n=1A093792
• Triangle T(n,k), the number of permutations on n elements that have no cycles of length k.at n=40A122974
• Triangle read by rows: T(n,k) = S1(n,k)*2^k, where S1(n,k) is an unsigned Stirling number of the first kind (cf. A008275) (n >= 1, 1 <= k <= n).at n=41A125553
• a(n) = Product_{k=1..n, gcd(k,n)=1} (1+k).at n=17A131553
• Coefficients of raising factorial polynomials, T(n,k) = [x^k] p(x, n) where p(x, n) = (m*x + n - 1)*p(x, n - 1) with p[x, 0] = 1, p[x, -1] = 0, p[x, 1] = m*x and m = 2. Triangle read by rows, for n >= 0 and 0 <= k <= n.at n=51A137320
• a(n) = (a(n-1)*a(n-2) + a(n-1)^2)/a(n-3), with a(1) = a(2) = a(3) = 1.at n=7A141609
• Integers with exactly 100 divisors.at n=26A163816
• Partial sums of A007202 (crystal ball sequence for hexagonal close-packing).at n=23A186707
• Number of (w,x,y,z) with all terms in {0,...,n} and max{w,x,y,z}>2*min{w,x,y,z}.at n=23A212743
• Triangle read by rows: T(n,k) (n>=1, 1 <= k <= n) = number of permutations of [1..n] in which none of the cycle lengths are divisible by k.at n=40A213280
• Number of permutations on n points admitting a fifth root.at n=9A215716