54459

Appears in sequences

• G.f.: Sum_{n>=0} [Sum_{k>=0} C(n+k-1,k)^2*x^k]^2 * x^n.at n=8A178807
• 1/4 the number of arrangements of 4 nonzero numbers x(i) in -n..n with the sum of sign(x(i))*(|x(i)| mod x(i+1)) equal to zero.at n=25A189953
• Diagonal sums of Riordan matrix A118384.at n=7A190725
• Odd numbers k such that A173557(k) = A173557(sigma(k)), where A173557(n) is multiplicative with a(p^e) = p-1 and sigma is the sum of divisors function.at n=44A387159