21209

Appears in sequences

• Number of series-reduced trees with n nodes.at n=23A000014
• Triangle read by rows: T(n,k) is the number of unlabeled directed graphs on n nodes with k arcs, k=0..n*(n-1).at n=55A052283
• Triangle read by rows: T(n,k) is the number of unlabeled directed graphs on n nodes with k arcs, k=0..n*(n-1).at n=67A052283
• Triangle T(n,k) of number of unilaterally connected digraphs on n unlabeled nodes with k arcs, k=0..n*(n-1).at n=66A057270
• Triangle T(n,k) of number of digraphs with a source on n unlabeled nodes with k arcs, k=0..n*(n-1).at n=66A057277
• Triangle T(n,k) of number of digraphs with a source and a sink on n unlabeled nodes and k arcs, k=0..n*(n-1).at n=66A057278
• Triangle T(n,k) of number of digraphs with a quasi-source on n unlabeled nodes and with k arcs, k = 0..n*(n-1).at n=66A057279
• How many more primes than irreducible GF(2)[X] polynomials there are in range [2^n,2^(n+1)].at n=20A091232
• Position of records in A034693.at n=17A194945
• Number of ordered triples (w,x,y) with all terms in {1,...,n} and w^3 < x^3 + y^3.at n=31A211650
• Numbers n such that the least prime of the form 2nk + 1 has a value of k that is larger than the k values for all smaller n.at n=13A239727
• First appearance of n in A016014, or 0 if n never occurs.at n=53A239800
• a(n) is the smallest number m such that 2im+1 is composite for all i, 0<i<n+1.at n=41A244433
• a(n) is the smallest number m such that 2im+1 is composite for all i, 0<i<n+1.at n=42A244433
• a(n) is the smallest number m such that 2im+1 is composite for all i, 0<i<n+1.at n=43A244433
• a(n) is the smallest number m such that 2im+1 is composite for all i, 0<i<n+1.at n=44A244433
• a(n) is the smallest number m such that 2im+1 is composite for all i, 0<i<n+1.at n=45A244433
• a(n) is the smallest number m such that 2im+1 is composite for all i, 0<i<n+1.at n=46A244433
• a(n) is the smallest number m such that 2im+1 is composite for all i, 0<i<n+1.at n=47A244433
• a(n) is the smallest number m such that 2im+1 is composite for all i, 0<i<n+1.at n=48A244433