27839
domain: N
Appears in sequences
- Denominators of continued fraction convergents to sqrt(14).at n=13A041021
- a(n) = floor(11^n/9^n).at n=51A094997
- Pell pseudoprimes: odd composite numbers n such that P(n)-Kronecker(2,n) is divisible by n.at n=29A099011
- Triangle read by rows: T(n,k) is the number of skew Dyck paths of semilength n and having k LDU's (n >= 0; 0 <= k <= floor((n-1)/3) for n >= 1).at n=15A128735
- Number of skew Dyck paths of semilength n and having no LDU's.at n=9A128736
- Expansion of x*(1+x)/(x^2-30*x+1).at n=3A157878
- Numbers k such that 2^(k+1) == 1 (mod k).at n=25A187787
- Composite numbers n such that b^(n+1) == 1 (mod n) for every b coprime to n.at n=13A208728
- Partial sums of the number of active (ON, black) cells in n-th stage of growth of two-dimensional cellular automaton defined by "Rule 411", based on the 5-celled von Neumann neighborhood.at n=33A271891
- Denominators of the convergents to sqrt(14)/2 = A294969.at n=13A295337
- Composite numbers k such that Pell(k) == 1 (mod k).at n=33A319042
- Number of series-reduced palindromic plane trees with n nodes.at n=28A319437