1743392201

Appears in sequences

• a(n) = (3^n + 1)/2.at n=20A007051
• a(n) = 2*a(n-1) + 3*a(n-2), a(0) = a(1) = 1.at n=20A046717
• Binomial transform of Jacobsthal gap sequence (A080924).at n=20A080925
• a(n) = (3^(2*n) + 1) / 2.at n=10A083884
• a(n) = n! * Sum_{i+2j+3k=n} 1/(i!*(2j)!*(3k)!).at n=21A094717
• a(n) = 3*a(n-1) + a(n-2) - 3*a(n-3).at n=20A103425
• 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=21A124302
• a(n) = 3*a(n-1) - a(n-3) + 3*a(n-4), with initial values 2,5,13,40.at n=19A133448
• a(n) = (3*3^n-(-1)^n)/2.at n=19A164907
• a(n) = (3^n+1)/(3-(-1)^n).at n=20A167205