309141

Appears in sequences

• Indices of octagonal numbers which are also 9-gonal.at n=2A048923
• a(n) = Sum_{k=0..floor(n/2)} binomial(n-k, k-1) * 4^(k-1).at n=15A099580
• a(n) = n*(n + 1)*(13*n^2 + 13*n - 14)/24.at n=27A264888
• Smallest positive integer that has exactly n representations of the form 1 + p1 * (1 + p2* ... * (1 + p_j)...), where [p1, ..., p_j] is a (possibly empty) list of distinct primes.at n=24A317385