Sequences

Number of perfect matchings in graph P_{3} X C_{4} X P_{n}.

Number of perfect matchings in graph P_{3} X C_{5} X P_{2n}.

Number of perfect matchings in graph P_{4} X C_{4} X P_{n}.

Number of perfect matchings in graph C_{3} X C_{3} X P_{2n}.

Number of perfect matchings in graph C_{3} X C_{4} X P_{n}.

Number of perfect matchings in graph C_{3} X C_{5} X P_{2n}.

Number of perfect matchings in graph C_{4} X C_{4} X P_{n}.

Number of perfect matchings in graph P_{6} X P_{n}.

Number of perfect matchings in graph P_{7} X P_{2n}.

Number of perfect matchings in graph P_{8} X P_{n}.

Number of perfect matchings (or domino tilings) in the graph P_9 X P_2n.

Number of perfect matchings in graph P_{10} X P_{n}.

Number of perfect matchings in graph P_{11} X P_{2n}.

Number of perfect matchings in graph P_{12} X P_{n}.

Total number of Hamiltonian cycles avoiding the root-edge in rooted cubic bipartite planar maps with 2n nodes.

Greatest k such that phi(k) = phi(n), where phi is Euler's totient function.

Number of perfect matchings in graph C_{6} X P_{n}.

Number of perfect matchings in graph C_{7} X P_{2n}.

Number of perfect matchings in graph C_{8} X P_{n}.

Number of perfect matchings in graph C_{9} X P_{2n}.

Number of perfect matchings in graph C_{10} X P_{n}.

Number of perfect matchings in graph C_{11} X P_{2n}.

Number of perfect matchings in graph C_{12} X P_{n}.

Number of perfect matchings in graph C_{13} X P_{2n}.

Number of perfect matchings in graph C_{14} X P_{n}.

Number of perfect matchings in graph C_{15} X P_{2n}.

Number of perfect matchings in graph C_{16} X P_{n}.

Numbers k such that the summatory Liouville function L(k) (A002819) is zero.

Duplicate of A005808.

Erroneous version of A004064.

Numbers k such that (3^k - 1)/2 is prime.

Number of similarity classes of triangles which can be drawn using the lattice points in an n X n grid for vertices.

a(0) = 16, a(n+1) = 3a(n) - (6-n)^2.

a(n) = -(1/2)*(n+2)*(n^2 - 6*n - 1).

Expansion of g.f. (1-x^2)/(1-x-2*x^2+x^3).

Erroneous version of A152455.

Maximum number of facets of n-dimensional polytope with {0,1}-coordinates.

Let [n] = {0,...,n-1}; a(n) is number of functions f:[n] -> [n] for which there exists an injection g:[n] -> [n+1] such that for j with 0 <= j < n, either g(j) = f(j) or g(j) = f(j)+1.

6-hyperperfect numbers: n = 6*(sigma(n) - n - 1) + 1.

12-hyperperfect numbers: n = 12*(sigma(n) - n - 1) + 1.

18-hyperperfect numbers: n = 18*(sigma(n)-n-1) + 1.

2772-hyperperfect numbers: n = 2772*(sigma(n)-n-1) + 1.

Numbers k such that k*(k+2) is a palindrome.

Palindromes of form k*(k+2); or palindromes 1 less than a square.

Number of primes <= 100*n.

Number of non-descending integral vectors b of length n such that number of symmetric 0-1-matrices A of order n with row sums <= b is odd.

Continued fraction expansion for log_2(3).

Continued fraction expansion for log_2(5).

Continued fraction expansion for log_2(7).

Continued fraction expansion for log_2(9).