5230176601

Appears in sequences

• a(n) = (3^n - 1)/2.at n=21A003462
• a(n) = 2*a(n-1) + 3*a(n-2), a(0) = a(1) = 1.at n=21A046717
• Binomial transform of Jacobsthal gap sequence (A080924).at n=21A080925
• a(n) = (3*9^n - 1)/2.at n=10A096053
• a(n) = 3*a(n-1) - a(n-3) + 3*a(n-4), with initial values 2,5,13,40.at n=20A133448
• a(n) = 3*a(n-1) - a(n-3) + 3*a(n-4), with initial values 2,4,13,40.at n=20A133453
• a(n) = (3^n-1)/2 if n odd, (3^n-1)/8 if n even.at n=21A152298
• a(n) = (3*3^n-(-1)^n)/2.at n=20A164907
• The 3 X 3 X ... X 3 dots problem (3, n times): minimal number of straight lines (connected at their endpoints) required to pass through 3^n dots arranged in a 3 X 3 X ... X 3 grid.at n=21A261547
• Numbers k such that there is an anti-divisor d of k satisfying sigma(d) = k.at n=34A286917
• Square array read by antidiagonals (upwards): A(n,k) = (k^Fibonacci(n) - 1) / (k - 1) for k >= 0 and n >= 0 with lim_{k -> 1} A(n,k) = A(n,1) = Fibonacci(n).at n=69A342689