55825

Appears in sequences

• Number of singular 2 X 2 matrices over Z(n) (i.e., with determinant = 0).at n=34A020478
• a(n) = n*(1+n^2)*((2+n^2)^2-n^2)/16.at n=6A094311
• Row sums of triangle A115237.at n=39A115238
• Least k with precisely n partitions k = x + y satisfying sigma(k) = sigma(x) + sigma(y).at n=23A211224
• Smallest zeroless number x such that x^n has exactly n zero digits.at n=21A233821
• Number of non-congruent solutions of x^2 + y^2 + z^2 + t^2 == 0 mod n.at n=34A240547
• Indices of records in A192013: Sum_{d|n} Kronecker(-6, d).at n=11A279541
• Occurrences of decrease of the probability density P(n) of coprime numbers k,m, satisfying 1 <= k <= a(n) and 1 <= m <= a(n), and a(n) congruent to 1 (mod 2) and a(n) not congruent to 3 (mod 6).at n=22A280879
• Number of n X 1 0..1 arrays with the number of 1's king-move adjacent to some 0 two less than the number of 0's adjacent to some 1.at n=19A286209
• Number of non-congruent solutions of x^2+y^2 == z^2+w^2 (mod n).at n=34A316148
• The denominators of the semiderivative of the Euler polynomials at x = 1 and normalized by sqrt(Pi).at n=18A346715
• a(n) = Sum_{1 <= x_1, x_2 <= n} sigma( n/gcd(x_1, x_2, n) ).at n=34A373129