21746
domain: N
Appears in sequences
- Number of 5-tuples of different integers from [ 1,n ] with no common factors among pairs.at n=36A015698
- Numbers k such that phi(k) | sigma_10(k).at n=21A015768
- Row sums of triangle A046527.at n=7A046814
- Pascal-(1,4,1) array.at n=59A081579
- Pascal-(1,4,1) array.at n=61A081579
- Define a sequence u(n) by u(1)=1; thereafter u(n) = f(n)/f(n-1) where f(n) = (-1)^(n+1)*A105750(n); sequence gives numerator(u(n)).at n=10A220448
- Number of length n+5 0..1 arrays with every six consecutive terms having the maximum of some three terms equal to the minimum of the remaining three terms.at n=14A250329
- Partial sums of the number of active (ON, black) cells in n-th stage of growth of two-dimensional cellular automaton defined by "Rule 225", based on the 5-celled von Neumann neighborhood.at n=32A270944
- Numbers k such that 477*2^k+1 is prime.at n=32A319487