1309959

Appears in sequences

• Number of nonempty subsets of {1,2,...,n} in which exactly 5/6 of the elements are <= (n+1)/3.at n=43A048048
• Number of nonempty subsets of {1,2,...,n} in which exactly 5/6 of the elements are <= (n+2)/3.at n=43A048081
• Partial sums of A051798.at n=26A051879
• Group the natural numbers >= 1 so that the n-th group contains n(n+1)/2 numbers and obtain the group sum.at n=26A095166