26221
domain: N
Appears in sequences
- Inverse Moebius transform of A000048 (starting at term 0).at n=20A054172
- Downward vertical of triangular spiral in A051682.at n=38A081272
- Numbers k such that (k / sum of digits of k) and (k+1 / sum of digits of k+1) are both prime.at n=24A085775
- Irregular triangle T(n,k) read by rows: number of orbits of size 2^k on Dyck n-paths.at n=38A175137
- a(n) = abs(a(n-1) - 3*a(n-2)) with a(1)=a(2)=1.at n=25A192263
- Odd composite numbers n, such that n, n+d, n*d and n/d are all odious (A000069) for every divisor d of n.at n=38A231558
- Partial sums of the number of active (ON, black) cells in n-th stage of growth of two-dimensional cellular automaton defined by "Rule 913", based on the 5-celled von Neumann neighborhood.at n=26A273768