a(n) = denominator of 3*Sum_{j=0..n+1} 1/(2*j+1).
A111877
a(n) = denominator of 3*Sum_{j=0..n+1} 1/(2*j+1).
Terms
- a(0) =1a(1) =5a(2) =35a(3) =105a(4) =1155a(5) =15015a(6) =15015a(7) =255255a(8) =4849845a(9) =4849845a(10) =111546435a(11) =557732175a(12) =1673196525a(13) =48522699225
External references
- oeis: A111877