317885

Appears in sequences

• a(n) is the index of the smallest triangular number containing exactly n 5's.at n=7A048360
• Analog of A006684 for the 5x+1 problem (cf. A133419).at n=23A133423
• Triangular array read by rows. T(n,k) is the number of labeled relations on n elements with exactly k vertices of indegree and outdegree = 0.at n=16A217436