423644304722
domain: N
Appears in sequences
- a(n) = (3^n + 1)/2.at n=25A007051
- Number of set partitions with at most 3 blocks; number of Dyck paths of height at most 4; dimension of space of symmetric polynomials in 3 noncommuting variables.at n=26A124302
- a(n) = 3*a(n-1) - a(n-3) + 3*a(n-4), with initial values 2,5,13,40.at n=24A133448
- a(n) = 3*a(n-1) - a(n-3) + 3*a(n-4), with initial values 2,4,13,40.at n=24A133453
- a(0) = 1 and a(n) = (3^n - (-1)^n)/2 for n >= 1.at n=25A152011
- a(n) = (3*9^n + 1)/2.at n=12A199560
- a(n) = (-1)^(n+1) * (3^n+1)/2.at n=25A341463
- Cogrowth sequence of the 18-element group S3 X C3 = <S,T,U | S^3, T^2, U^3, (ST)^2, [S,U], [T,U]>.at n=27A378109