2615088301

Appears in sequences

• a(n) = (1 - (-3)^n)/4.at n=21A014983
• a(n) = 2*a(n-1) + 3*a(n-2), with a(0)=0, a(1)=1.at n=21A015518
• Number of distinct paths of length 2n+1 along edges of a unit cube between two fixed adjacent vertices.at n=10A066443
• Numbers of the form (3^s+1)/(3^r+1) for s > 1, 1 <= r <= s-1.at n=19A079672
• a(n) = (2 + (-1)^n + 3^n)/4.at n=21A122983
• a(n) = 3*a(n-1) - a(n-3) + 3*a(n-4), with initial values 1,3,7,20.at n=20A132868
• Numbers occurring in A137822 : first differences of numbers n such that 3 | sum( Catalan(k), k=1..2n).at n=30A137823
• a(n) = (3^n+1)/(3-(-1)^n).at n=21A167205
• Row sums of triangle in A287879, divided by 2.at n=20A287880
• a(n) = p(0,n), where p(x,n) is the strong divisibility sequence of polynomials based on sqrt(3) as in A327321.at n=20A329008
• a(0) = 0; for n >= 1, one quarter of the number of points on the elliptic curve y^2 = x^3 - x defined over GF(3^n).at n=21A382171