4048551936

Appears in sequences

• Triangle read by rows: T(n,k) is the number of closed binary operations on a set of n labeled elements with a closed center of size k.at n=10A386681
• a(n) is the number of closed binary operations on a set of n labeled elements with empty center.at n=4A391094
• Triangle read by rows: T(n,k) is the number of labeled magmas with n elements whose center contains k elements.at n=10A391154