27449

Properties

Appears in sequences

• a(0), a(1), a(2), ... satisfy Sum_{k=0..n} a(k)*binomial(n,k) = 2^binomial(n,2), for n >= 0.at n=6A006129
• Smallest prime containing n-th cube as substring.at n=14A029949
• Smallest nontrivial extension of n-th cube which is a prime.at n=13A030692
• a(n) = prime(100*n).at n=29A031921
• a(n) = prime(1000 * n).at n=2A031922
• Places k where A064608(k) (partial sums of unitary tau) is divisible by k.at n=6A064610
• Number of graphs on n labeled nodes with degree at most 4.at n=5A136283
• Primes that become squares when prefixed with a 1.at n=3A167734
• Triangular array read by rows T(n,k) is the number of simple labeled graphs on n nodes with exactly k isolated nodes, 0<=k<=n.at n=21A198261
• Primes of the form 10n^3+9.at n=4A201306
• Primes of the form 2*n^2+38*n+17.at n=41A243890
• Numbers n such that n!!-16 is prime.at n=18A258616
• Regular triangle where T(n,k) is the number of labeled k-uniform hypergraphs spanning n vertices.at n=16A299471
• a(0) = a(1) = 1, a(n) = largest natural number m <= a(n-1) + a(n-2) where gcd(m,a(k)) = 1 for all 1 < k <= n-1.at n=23A345020
• Triangle read by rows where T(n,k) is the number of labeled graphs with n vertices and k non-isolated vertices.at n=27A370319
• Prime numbersat n=3000