1040257
domain: N
Appears in sequences
- Numbers that are a product of distinct Mersenne primes (elements of A000668).at n=26A046528
- Sum of divisors of n, sigma(n) (A000203), is a power of number of divisors of n, d(n) (A000005).at n=17A051281
- Numbers n such that sigma(n) is a prime power (A025475).at n=27A065523
- Semiprimes that are a product of Mersenne primes.at n=15A144482
- Semiprimes that are a product of distinct Mersenne primes.at n=11A144856
- Products of 2 successive Mersenne primes.at n=3A165223
- Numbers n with the property that there are integers k, h such that sigma(n) = k^tau(n) = tau(n)^h.at n=6A225362
- Nonprime numbers k such that sum of the divisors of k is a power of 2.at n=19A254603
- a(n) is the largest number k such that sigma(k) = 2^n or 0 if no such k exists.at n=20A295043
- Irregular table read by rows; the n-th row contains in ascending order the integers m > 1 such that sigma(m) = tau(m)^n; the first row contains 1.at n=24A349838