42520

Appears in sequences

• a(n) = Sum_{k=1..n} k*[ (n/k)*[ (n/k)*[ n/k ] ] ].at n=29A024933
• Triangle read by rows: T(n,k) is the number of Dyck paths of semilength n having k DUDU's starting at level 1.at n=47A135333
• Number of Dyck paths of semilength n having no DUDU's starting at level 1.at n=11A135339
• Number of nX6 0..4 arrays with each element equal to the number its horizontal and vertical neighbors equal to 2.at n=11A197059
• Number of (n+1) X 2 0..3 arrays containing all values 0..3 with every 2 X 2 subblock having three distinct values, and new values 0..3 introduced in row major order.at n=4A210260
• Number of (n+1)X6 0..3 arrays containing all values 0..3 with every 2X2 subblock having three distinct values, and new values 0..3 introduced in row major order.at n=0A210264
• T(n,k)=Number of (n+1)X(k+1) 0..3 arrays containing all values 0..3 with every 2X2 subblock having three distinct values, and new values 0..3 introduced in row major order.at n=10A210267
• T(n,k)=Number of (n+1)X(k+1) 0..3 arrays containing all values 0..3 with every 2X2 subblock having three distinct values, and new values 0..3 introduced in row major order.at n=14A210267
• Least number k such that (n!+k)/n and (n!-k)/n are both prime.at n=37A245697
• a(n) is the smallest k such that sigma(sigma(k)) = sigma(sigma(k) - k) + n*k, or 0 if no such k exists.at n=5A292413