244800

Appears in sequences

• Sum of divisors of those numbers n such that n and n+1 have the same sum of divisors.at n=30A053215
• Sigma(A033631(n)) {sigma is the sum of divisors function A000203}.at n=29A115619
• Nonnegative values x of solutions (x, y) to the Diophantine equation x^2 + (x+511)^2 = y^2.at n=34A207078
• Integer areas A of integer-sided cyclic quadrilaterals such that the circumradius is of prime length.at n=40A230136
• The number of positive integer sequences of length n with no duplicate substrings (forward or backward) of length greater than 1, every number different from its neighbors, and a minimal sum (= A282167(n)).at n=16A284433
• Regular triangle T(n,k) = binomial(2*n-2*k,n-k)*((n+1)/k)*Sum_{k=0..floor((k-1)/2)} (-1)^k*binomial(2*k,k)*binomial(n+3*k-2*k,k-2*k-1), read by rows.at n=32A306625
• a(n) is the product of the distinct nonzero quadratic residues of n.at n=31A372651