25369

Appears in sequences

• Expansion of e.g.f. cos(sin(arctan(x))) (even powers).at n=4A012023
• Expansion of e.g.f. exp(tan(arcsin(x))).at n=8A012150
• Odd composite n such that phi(n) * sigma(n) is one less than a square.at n=18A015722
• Number of free n-ominoes with cell centers determining n-2 space (proper dimension n-2).at n=9A036364
• Expansion of e.g.f.: cosh(x/sqrt(1-x^2)) (even powers).at n=4A081442
• Number of permutations of [n] avoiding the pattern 143-2.at n=7A200404
• Composite numbers k such that phi(k) * psi(k) + 1 is a perfect square, where phi is the Euler totient function (A000010) and psi is the Dedekind psi function (A001615).at n=37A309653
• Number of integer partitions of n with sortable prime factors.at n=40A326333
• Odd composite integers m such that A001906(m-J(m,5)) == 0 (mod m) and gcd(m,5)=1, where J(m,5) is the Jacobi symbol.at n=38A340097
• Number of nonnegative solutions to (x_1)^2 + (x_2)^2 + ... + (x_10)^2 <= n.at n=14A341405
• a(n) = Sum_{1 <= x_1, x_2 <= n} ( n/gcd(x_1, x_2, n) )^3.at n=7A372950