1556480

Appears in sequences

• 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 (2,9)-perfect numbers.at n=4A019286
• a(1) = 4; a(n) = smallest composite number greater than the sum of all previous terms.at n=19A070232
• (2,k)-perfect numbers (A019278) such that the next (2,k)-perfect number has the same value of k (in A098223).at n=6A205643
• Numbers n such that denominator(sigma(sigma(n))/n) = denominator(sigma(sigma(s))/s) where s = sigma(n).at n=27A275321
• Subsequence of terms of A019278 whose sum of divisors is also a term of A019278.at n=18A292949
• Heinz numbers of integer partitions, with at least three parts, whose product of parts is one fewer than their sum.at n=26A325043
• Array read by antidiagonals: A(n,k) is the number of nonnegative integer matrices with k columns and any number of nonzero rows with column sums n and columns in nonincreasing lexicographic order.at n=52A331315
• Number of nonnegative integer matrices with 2 distinct columns and any number of nonzero rows with column sums n and columns in decreasing lexicographic order.at n=7A331397