3755844
domain: N
Appears in sequences
- a(n) = binomial(n+5,5) * binomial(n+5,4)/(n+5).at n=15A006857
- Number of nonempty subsets of {1,2,...,n} in which exactly 1/6 of the elements are <= n/3.at n=27A048001
- Number of nonempty subsets of {1,2,...,n} in which exactly 1/6 of the elements are <= (n-1)/3.at n=27A048014
- Number of nonempty subsets of {1,2,...,n} in which exactly 1/6 of the elements are <= (n+1)/3.at n=27A048047
- Numbers k such that the sets of prime factors (ignoring multiplicity) of A000203(k) = sigma(k) and of A001157(k) = sigma_2(k) are identical.at n=20A081380
- a(n) = ((n-1)^2*n^2*(n+1)^2)/6 - 2*Sum_{l=2..n}Sum_{k=2..n}(n-k+1)*(n-l+1)*(k-1)*(l-1).at n=18A169801
- Areas of primitive Heronian triangles K which are perfect squares.at n=38A248108