3500640

Appears in sequences

• a(n+1) = a(n)/n if n|a(n) else a(n)*n, a(1) = 1.at n=17A008336
• a(n) = 2^A006218(n)/( (n!)^2*Sum_{m=0..n} 1/(m!*(2*n-m+1)!) ).at n=8A178345
• a(n) = A000108(n)*A002605(n+1), where A000108 are the Catalan numbers.at n=8A185020
• Triangle read by rows: T(n,k) (n>=2, 1<=k<=n-1) is the number of unordered pairs of vertices at distances k in the odd graph O_n.at n=30A228308
• Numbers of the form p^2-1 that have a record-breaking number of divisors, where p is prime.at n=17A323278
• A008336 sorted and duplicates removed.at n=19A370968