42540
domain: N
Appears in sequences
- The least k such that A063994(k) = Product_{primes p dividing k} gcd(p-1, k-1) = n, or 0 if there's no such k.at n=58A064234
- Numbers k such that the number of primes between k and 2k (inclusive) is equal to the number of primes between k and reverse(k) (inclusive).at n=36A074814
- Triangle read by rows: T(n,k) = the number of Dyck paths of semilength n with k UDDU's.at n=37A135306
- Number of Dyck paths of semilength n that do not contain the string UDDU.at n=12A135307
- Number of permutations of 2 copies of 1..n avoiding adjacent step pattern up, up.at n=5A177555
- Sum of largest parts of all partitions of n into an even number of parts.at n=32A222048
- a(n) = Sum_{1 <= i, j, k <= n} gcd(i,j,k).at n=31A344522
- Composite k such that the primorial inflation of k is a sum of distinct primorial numbers.at n=28A351959