24882
domain: N
Appears in sequences
- Number of n-step spirals on hexagonal lattice.at n=17A006778
- n satisfying sigma(n+1) = sigma(n-1).at n=29A055574
- Numbers n such that the arithmetic, geometric and harmonic means of phi(n) and sigma(n) are all integers.at n=17A065146
- Numbers k such that sigma(k-1) divides sigma(k+1).at n=35A067130
- Numbers n such that sum of distinct primes dividing n is divisible by the largest prime dividing n. Also n is neither a prime, nor a true power of prime and n is squarefree. Squarefree solutions of A071140.at n=27A071141
- Numbers n such that sum of distinct primes dividing n is divisible by the largest prime dividing n. Also n has exactly 5 distinct prime factors and n is squarefree.at n=7A071144
- Squarefree numbers k such that the largest prime factor of k is equal to the sum of the other prime factors of k.at n=26A071312
- Squarefree balanced numbers (i.e., squarefree members of A020492).at n=38A078557
- Even numbers k such that the central binomial coefficient A000984(k, k/2) is divisible by k^2.at n=14A080395
- Squarefree numbers sandwiched between two brilliant numbers.at n=3A085706
- Numbers such that Sigma(m)*UnitarySigma(m)= k*UnitaryPhi(m)^2, for some integer k.at n=44A122839
- Numbers m such that UnitarySigma(m)^2 = k*Sigma(m)*UnitaryPhi(m), for some integer k.at n=44A123041
- Numbers k such that sigma(k) = 9*phi(k).at n=10A163667
- a(n) = (n^5 - n)/10, which is always an integer.at n=11A164938
- Numbers n such that sigma(n+1) - sigma(n-1) = k*n for some integer k, where sigma(n) = A000203 (sum of divisors of n).at n=30A223137
- Numbers k such that sigma(k+1) divides sigma(k-1).at n=30A227304
- Number of ways to partition the multiset consisting of n copies each of 1, 2, and 3 into n sets of size 3.at n=19A254233
- Numbers x such that (-1)sigma(x) | sigma(x), where (-1)sigma(x) is defined in A049060 and sigma(x) is the sum of the divisors of x (A000203).at n=46A258077
- Squarefree numbers k such that alpha(k) = lambda(k), where alpha(k) = LCM of all (p+1) for primes p dividing k, and lambda(k) = A002322(k).at n=6A287514
- Non-primitive balanced numbers: balanced numbers of the form m*n where m, n > 1 are both balanced.at n=38A291566