31350

Appears in sequences

• T(4n,n), where T is the array defined in A025177.at n=5A025186
• T(4n,n), where T is the array in A026148.at n=5A026159
• Least area of primitive Pythagorean triangle whose legs differ by A058529(n).at n=39A094143
• Area of the Pythagorean triangle a = u^2 - v^2 (cf. A096382) when u=3, v=4,4,5,...at n=18A096383
• G.f. A(x) satisfies: 4^n/2 = Sum_{k=0..n} [x^k]A(x)^n and also satisfies: ((4+z)^n + z^n)/2 = Sum_{k=0..n} [x^k](A(x)+z*x)^n for all z, where [x^k]A(x)^n denotes the coefficient of x^k in A(x)^n.at n=19A100240
• Third partial sums of fourth powers (A000583).at n=7A101090
• Values of z arising from representations of n >= 11 in A085514.at n=38A102777
• Enneagonal numbers for which the product of the digits is also an enneagonal number.at n=32A117052
• a(n) = n*(n-1)*(n+1)*(3*n-2)/12.at n=18A153978
• Eleven times hexagonal numbers: a(n) = 11*n*(2*n-1).at n=38A154617
• Partial sums of Sum_{k=1..n} n/gcd(n,k), or partial sums of Sum_{d|n} d*phi(d) (see A057660).at n=49A174405
• Triangle read by rows: T(n,k) is the number of non-equivalent regular polygons with n+1 edges, one of which is rooted, which are dissected by non-intersecting diagonals into k regions, such that two such polygons are identified up to reflection along the rooted edge and twisting along the diagonals that does not affect the root edge (for 1 <= k <= n-1 and n >= 2).at n=62A232206
• Unitary practical numbers that are nonsquarefree.at n=22A287173
• Number of canonical forms for separation coordinates on hyperspheres S_n, ordered by increasing number of independent continuous parameters.at n=58A295380
• Consider primitive pairs of integers (b, c) with b > 0 such that x^5 + b*x + c = 0 is irreducible and solvable by radicals: sequence gives values of b.at n=33A371553
• Consider primitive pairs of integers (b, c) with b > 0 such that x^5 + b*x + c = 0 is irreducible and solvable by radicals: sequence gives values of b.at n=34A371553
• Expansion of e.g.f. (x^2/(1-x)^3)*exp(x/(1-x)).at n=6A386961