100720

Appears in sequences

• Number of nondecreasing sequences of 6 1..n integers with no element dividing the sequence sum.at n=20A212873
• a(n) = Sum_{ i=2..n-1, j=1..i-1, gcd(i,j)=1 } (n-i)*(n-j).at n=33A332612
• a(n) is the number of semi-meanders with n top arches that have at least one arch with length 1 adjacent to the center of the top arch configuration or at either end of the arch configuration.at n=12A333971