116508

Appears in sequences

• Numbers j such that sigma(sigma(j)) = k*j for some k.at n=38A019278
• Let sigma_m (n) be result of applying sum-of-divisors function m times to n; call n (m,k)-perfect if sigma_m (n) = k*n; sequence gives the (2,8)-perfect numbers.at n=8A019285
• Base-4 digits are, in order, the first n terms of the periodic sequence with initial period 1,3,0.at n=8A037597
• Expansion of x^3/(1 - 2*x + x^3 - 2*x^4) = x^3/( (1-2*x)*(1+x)*(1-x+x^2) ).at n=20A113405
• First differences of A131666.at n=20A131090
• a(n) = floor(2^n/9).at n=20A153234
• Numbers of form 4^(3*k+l+1)/9 - 4^l/9 - 1/3 or 2*4^(3*k+l+2)/9 - 2*4^l/9 - 1/3, k,l>=0.at n=36A172143
• a(n) = (1/18)*(8^n - (-1)^n - 9).at n=6A172241
• Floor(1/{(9+n^4)^(1/4)}), where {} = fractional part.at n=63A184633
• Numbers n such that denominator(sigma(sigma(n))/n) = denominator(sigma(sigma(s))/s) where s = sigma(n).at n=21A275321
• Subsequence of terms of A019278 whose sum of divisors is also a term of A019278.at n=14A292949