Sequences

Number of 4-voter voting schemes with n linearly ranked choices.

a(n) = smallest pseudoprime to base 2 with n prime factors.

a(n) is number of k for which C(n,k) is not divisible by n.

Catalan-Mersenne numbers: a(0) = 2; for n >= 0, a(n+1) = 2^a(n) - 1.

Largest prime <= Product prime(k).

a(n) = smallest k such that phi(n+k) = phi(k).

Number of permutations of length n with 1 fixed and 1 reflected point.

Number of motifs in triangular window of side n.

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

a(n) = (2n+1)! / 2^n.

Maximal planar degree sequences with n nodes.

Number of 4-connected simplicial polyhedra with n nodes.

Number of 4-regular polyhedra with n nodes.

Number of 4-connected 4-regular polyhedra with n nodes.

Number of polyhedral graphs with n faces and minimal degree 4.

Number of polyhedral graphs with n nodes and minimal degree 4.

Number of 4-connected polyhedral graphs with n faces.

Number of 4-connected polyhedral graphs with n nodes.

Number of bipartite polyhedral graphs with n nodes.

Number of bipartite polyhedral graphs with n faces.

Non-Hamiltonian simplicial polyhedra with n nodes.

Non-Hamiltonian 1-tough simplicial polyhedra with n nodes.

Number of non-Hamiltonian polyhedra with n faces.

Number of non-Hamiltonian polyhedra with n nodes.

Noncircumscribable simplicial polyhedra with n nodes.

Number of non-1-Hamiltonian simplicial polyhedra with n nodes.

Number of 1-supertough but non-1-Hamiltonian simplicial polyhedra with n nodes.

Noninscribable simplicial polyhedra with n nodes.

Theta series of 20-dimensional lattice R_20 with det 1024 and minimal norm 4.

Number of cyclic binary n-bit strings with no alternating substring of length > 2.

Number of (marked) cyclic n-bit binary strings containing no runs of length > 2.

State assignments for n-state machine.

Left diagonal of partition triangle A047812.

Number of noncommutative SL(2,C)-invariants of degree n in 5 variables.

Left diagonal of partition triangle A047812.

Second (lower) diagonal of partition triangle A047812.

Number of irreducible positions of size n in Montreal solitaire.

Number of chains in power set of n-set.

Number of irreducible positions of size n in Montreal solitaire.

Number of irreducible positions of size n in Montreal solitaire.

Number of irreducible positions of size n in Montreal solitaire.

a(n) = (3^n + 1)/2.

Number of order-consecutive partitions of n.

Number of primes <= 2^n.

Super ballot numbers: 6(2n)!/(n!(n+2)!).

Let S denote the palindromes in the language {0,1}*; a(n) = number of words of length n in the language SS.

Let S denote the palindromes in the language {0,1,2}*; a(n) = number of words of length n in the language SS.

Let S denote the palindromes in the language {0,1,2,3}*; a(n) = number of words of length n in the language SS.

Let S denote the palindromes in the language {0,1,2,3,4}*; a(n) = number of words of length n in the language SS.

Number of balanced ordered trees with n nodes.