392448

Appears in sequences

• Reverse and add (in binary) - written in base 10.at n=27A035522
• Trajectory of 22 under the Reverse and Add! operation carried out in base 2.at n=26A061561
• Numbers m such that the sum of the first k divisors of m is equal to m for some k.at n=10A064510
• Numbers n such that (n, sigma(n)) lies on the hyperbola y^2 - x^2 = m^2, for some natural number m, i.e., sigma(n)^2 - n^2 = m^2.at n=2A066784
• a(n) = 3*2^(n-1)*(2^n-1).at n=8A103897
• a(n) = 2*a(n-1) + 2*a(n-2) - 4*a(n-3) with n>2, a(0)=0, a(1)=1, a(2)=3.at n=18A135094
• Erdős-Nicolas numbers.at n=5A194472
• Trajectory of 26 under the Reverse and Add! operation carried out in base 2.at n=24A213012
• Numbers n with the property that, if tau(n) = k = number of divisors of n, and the d(i) are the divisors [arranged in increasing order], then the sum 1/d(k) + 1/d(k-1) + 1/d(k-2) + ... + 1/d(q) is an integer for some q.at n=17A226476
• Triangle read by rows: T(n, k) is the smallest x such that the denominator of sigma(x)/x is equal to n and the numerator of sigma(x)/x is congruent to k modulo n.at n=55A242370
• Number of 4 X n 0..2 arrays with no element equal to any value at offset (-2,-2) (-1,-2) or (0,-1) and new values introduced in order 0..2.at n=9A275144
• Numbers k such that (sigma(k) - k)^(sigma(k) - k) == k (mod sigma(k)), where sigma = A000203.at n=40A375790