Sequences

a(n) = 6*a(n-1) - a(n-2), n >= 2, a(0)=1, a(1)=9.

a(n) = 6*a(n-1) - a(n-2) for n >= 2, with a(0)=3, a(1)=13.

Triangular matrix arising in enumeration of catafusenes, read by rows.

a(n) = (9*n^2 + 3*n + 2)/2.

Next-to-last diagonal of A024462.

Triangle giving number of unbranched catapolytetragons, read by rows.

Numbers k for which k-th primorial + square of (k+1)-th prime is also a prime.

Primes of the form A002110(k) + prime(k+1)^2.

Number of digits of n which are divisors of n.

Numbers divisible by at least one of their digits.

a(n) is the smallest composite number c such that A002110(n) + c is prime.

Numbers not divisible by any of their digits.

a(n) is the smallest prime of the form Q + c, where Q is the n-th primorial and c is a composite >= prime(n+1)^2.

Cycle lengths of the permutation that converts the forest of depth-first planar planted binary trees into breadth-first representation.

a(n) is the number of cycles of the permutation that converts forest(n) of depth-first planar planted binary trees into breadth-first representation.

The sequence a[1] to a[ cat[n] ] is the permutation that converts forest[n] of depth-first planar planted binary trees into breadth-first representation.

Number of nonisomorphic circulant directed p^2-graphs, indexed by odd primes p.

Circulant directed p^2-graphs up to rotations only, indexed by odd primes p.

An intermediate sequence for nonisomorphic circulant directed p^2-graphs, indexed by odd primes p.

An intermediate sequence for counting nonisomorphic circulant directed p^2-graphs, indexed by odd primes p.

Number of nonisomorphic circulant undirected p^2-graphs, indexed by odd primes p.

Circulant undirected p^2-graphs up to rotations only, indexed by odd primes p.

An intermediate sequence for nonisomorphic circulant undirected p^2-graphs, indexed by odd primes p.

An intermediate sequence for nonisomorphic circulant undirected p^2-graphs, indexed by odd primes p.

Number of nonisomorphic circulant self-complementary directed p^2-graphs, indexed by odd primes p.

Circulant self-complementary directed p^2-graphs up to rotations only, indexed by odd primes p.

An intermediate sequence for nonisomorphic circulant self-complementary directed p^2-graphs, indexed by odd primes p.

Non-Cayley-isomorphic circulant self-complementary directed p^2-graphs, indexed by odd primes p.

Number of nonisomorphic circulant p^2-tournaments, indexed by odd primes p.

Circulant p^2-tournaments up to rotations only, indexed by odd primes p.

An intermediate sequence for nonisomorphic circulant p^2-tournaments, indexed by odd primes p.

Rectangular array defined by T(i,1) = T(1,j) = 1 for i >= 1 and j >= 1; T(i,j) = max(T(i-1,j) + T(i-1,j-1), T(i-1,j-1) + T(i,j-1)) for i >= 2, j >= 2, read by antidiagonals.

T(n,n-3), array T as in A038792.

T(n,n-4), array T as in A038792.

T(n,n-5), array T as in A038792.

T(n,n-6), array T as in A038792.

T(n+4,n), array T as in A038792.

T(2n+5,n), array T as in A038792.

T(2n+6,n), array T as in A038792.

Number of primes between 10n and 10n+9.

Number of primes less than 10n.

Factor 2n+1 = (2^m1)*(3^m2)*(5^m3)*...; a(n) = number of initial zero exponents.

Largest number with n prime factors all of different lengths.

Difference between largest n-digit prime and smallest (n+1)-digit prime.

Difference between last prime < 10^n and 10^n is a record high.

Convolution of A008549 with A000302 (powers of 4).

Future of the smallest-perizeroin komet in Kimberling's expulsion array (A035486).

Palindromic numbers which are the difference of two positive cubes.

a(n) is the number of ways to write n in bases 2-10 such that the digit k-1 appears in the representation in base k.

a(n) is the number of ways to write the number n as dk...di...d2d1d0 where digit di represents di * (di+1)^i, restricting di to 0..9.