66002

Appears in sequences

• Number of walks within N^2 (the first quadrant of Z^2) starting at (0,0), ending on the vertical axis and consisting of n steps taken from {(-1, -1), (0, -1), (0, 1), (1, 0), (1, 1)}.at n=10A151444
• a(n) = Sum_{k=0..[n/2]} binomial((n-k)^2, n*k-k^2).at n=6A209331
• Numbers n such that 8*9^n - 1 is prime.at n=15A268356
• a(n) is the number of ordered 6-tuples (a_1,a_2,a_3,a_4,a_5,a_6) having all terms in {1,...,n} such that there exists a tetrahedron ABCD with those edge-lengths, taken in a particular order (see comments).at n=9A349295