13136773
domain: N
Appears in sequences
- a(n) = 2*a(n-1) + a(n-2) - a(n-3) for n >= 3, starting with a(0) = 1, a(1) = 3, and a(2) = 6.at n=20A006356
- Bottom line of 3-wave sequence A038196, also bisection of A006356.at n=10A038223
- Expansion of (1-x)/(1-2*x-x^2+x^3).at n=21A077998
- Expansion of x*(1-x)/(1-2*x-x^2+x^3).at n=22A106803
- a(n) is the number of symmetrical linear hydrocarbon chains with n C-C bonds.at n=39A370377
- Expansion of x + 1/(-x - 1/(-x - 1/(-x + 1))).at n=20A373567