a(n) = Sum_{i_1=0..3} Sum_{i_2=0..3} ... Sum_{i_n=0..3} multinomial(i_1+i_2+...+i_n; i_1, i_2, ... , i_n).
A308294
a(n) = Sum_{i_1=0..3} Sum_{i_2=0..3} ... Sum_{i_n=0..3} multinomial(i_1+i_2+...+i_n; i_1, i_2, ... , i_n).
Terms
- a(0) =1a(1) =4a(2) =69a(3) =5248a(4) =1107697a(5) =492911196a(6) =396643610629
External references
- oeis: A308294