293760

Appears in sequences

• Expansion of log(1+x)*log(1+tanh(x))/2.at n=10A024331
• Numbers k such that the set of prime divisors of k is equal to the set of prime divisors of sigma(k).at n=29A027598
• Value of phi in arithmetic progression of at least 5 terms having the same value of phi in A050515.at n=5A050517
• Smallest k such that d(phi(k)) - phi(d(k)) = -n, where d(k) = A000005(k) and phi(k) = A000010(k).at n=21A078151
• Lower triangular array called S1hat(3) related to partition number array A144880.at n=37A144881
• Second column (m=2) of triangle A144881 (S1hat(3)).at n=7A144883
• Weight distribution of [255,55,63] primitive binary BCH code.at n=71A151934
• Numbers n such that gcd(sigma(n), n) > gcd(sigma(m), m) for all m < n.at n=15A216793
• Numbers k for which sigma(k)/k - 3/4 is an integer.at n=2A218405
• Numbers k such that sigma(k) mod k = antisigma(k) mod k, where sigma(k) = A000203(k) = sum of divisors of k, antisigma(k) = A024816(k) = sum of non-divisors of k.at n=8A229088
• Numbers n such that tau(n)*sigma(n) divides n^2.at n=3A245787
• Smallest x such that sigma(x)/x = 2*sigma(n)/n where sigma(n) is the sum of divisors of n.at n=7A246827
• Square array read by antidiagonals: T(n,k) is the number of k-edge colored trees on vertex set [n] (n>=2, k>=2).at n=25A248090
• Numbers k such that k = Sum_{i=1..j} (d_i mod d), where d_i are their aliquot parts and d is one of them.at n=25A265646
• Denominators of r(n) := Sum_{k=0..n-1} 1/Product_{j=0..4} (k + j + 1), for n >= 0, with r(0) = 0.at n=14A300299
• Numbers k such that k divides lcm(tau(k), sigma(k)).at n=21A307740
• a(n) = n * 2^(n - 2) * (2^(n - 1) - 1).at n=9A308700
• Expansion of e.g.f. Product_{k>=1} (1 + x^prime(k)/prime(k)).at n=10A319113
• Numbers k such that the squarefree kernel of sigma(k) is equal to the squarefree kernel of 2*k.at n=31A332208
• T(n, k) = [x^k] 2^n*(Euler(n, x/2) + Euler(n, x)), where Euler(n, x) are the Euler polynomials. Triangle read by rows, T(n, k) for 0 <= k <= n.at n=58A342314