Sequences

Position of first occurrence of n in the continued fraction for the Laplace's limit constant.

Incrementally largest terms in the continued fraction for Laplace's limit constant.

Positions of the incrementally largest terms in the continued fraction for Laplace's limit constant.

Number of blocks of {1,0} in the binary expansion of n.

Number of i such that d(i) >= d(i-1), where Sum_{i=0..m} d(i)*2^i is the base-2 representation of n.

Numbers n such that every genus of binary quadratic forms of discriminant -4n consists of a single class and the class number h(-4n) = 2.

Numbers n such that every genus of binary quadratic forms of discriminant -4n consists of a single class and the class number h(-4n) = 4.

Numbers n such that every genus of binary quadratic forms of discriminant -4n consists of a single class and the class number h(-4n) = 8.

Numbers n such that every genus of binary quadratic forms of discriminant -4n consists of a single class and the class number h(-4n) = 16.

Number of odd primes <= n.

Number of odd nonprimes <= n.

Number of odd nonprimes dividing n.

Number of nonprime divisors of n.

Primes that do not contain any other prime as a proper substring.

Number of diagonal dissections of an n-gon into 3 regions.

Number of diagonal dissections of an n-gon into 4 regions.

Number of diagonal dissections of an n-gon into 5 regions.

Number of diagonal dissections of an n-gon into 6 regions.

Number of diagonal dissections of an n-gon into 7 regions.

Number of diagonal dissections of a convex (n+8)-gon into n+1 regions.

Number of diagonal dissections of a convex (n+9)-gon into n+1 regions.

Triangle read by rows: T(n, k) is the number of diagonal dissections of a convex n-gon into k+1 regions.

Numbers whose maximal base-10 run length is 2.

Numbers whose maximal base-10 run length is 3.

Numbers whose maximal base-10 run length is 4.

a(n) = n * prime(n).

First differences of A033286.

Theta series of 20-dimensional lattice L_20 with group 2.M_22.2.

Odd power perfect numbers: numbers k such that opsigma(k) = 2*k, where opsigma(k) = A033634(k).

Ten consecutive primes in arithmetic progression.

A Connell-like sequence: take the first multiple of 1, the next 2 multiples of 2, the next 3 multiples of 3, etc.

A Connell-like sequence: take 1 number = 1 (mod Q), 2 numbers = 2 (mod Q), 3 numbers = 3 (mod Q), etc., where Q = 3.

A Connell-like sequence: take 1 number = 1 (mod Q), 2 numbers = 2 (mod Q), 3 numbers = 3 (mod Q), etc., where Q = 8.

Squares which when written backwards remain square (final 0's excluded).

a(n) = [ Gamma(sqrt(n)) ].

Number of paths from (0,0) to (3n,0) that stay in first quadrant (but may touch horizontal axis), where each step is (2,1),(1,2) or (1,-1) and start with (1,2).

Number of ordered rooted trees with n edges such that the rightmost leaf of each subtree is at even level. Equivalently, number of Dyck paths of semilength n with no return descents of odd length.

a(n+1) = a(n) + sum of digits of a(n)^2, with a(1) = 1.

Smallest safe prime ((p-1)/2 is also prime) > n.

Smallest safe prime ((p-1)/2 is also prime) > n-th prime.

Number of 4-valent (or quartic) graphs with n nodes.

Largest prime < largest prime < n.

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

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

Number of permutations (p1,...,pn) such that 1 <= |pk - k| <= 2 for all k.

Triangle of coefficients of ordered cycle-index polynomials: T(n,k) = binomial(n,k)*Bell(k)*Bell(n-k).

Decimal expansion of Champernowne constant (or Mahler's number), formed by concatenating the positive integers.

Decimal expansion of Copeland-Erdős constant: concatenate primes.

Position of first occurrence of n in continued fraction for Copeland-Erdős constant.

Incrementally largest terms in continued fraction for Copeland-Erdős constant.