Sequences

Left-hand border of triangle A046937.

Let a (resp. b,c,d) be number of primes in the range {2..p} that end in 1 (resp. 3,7,9); sequence gives p such that a=d and b=c.

Indices of primes appearing in A038562.

Numbers whose list of divisors includes each digit 1-9 equally often.

Number of times digits are repeated in A038564.

Numerators in canonical bijection from positive integers to positive rationals <= 1: arrange fractions by increasing denominator then by increasing numerator.

Denominators in canonical bijection from positive integers to positive rationals <= 1.

Numerators in canonical bijection from positive integers to positive rationals.

Denominators in a certain bijection from positive integers to positive rationals.

Second derivative of n.

Number of times n must be differentiated to reach 0.

a(n) = n rotated one binary place to the right.

a(n) = 2^A000120(n) - 1.

Write n in ternary, sort digits into increasing order.

Number of prime factors of n-th Fibonacci number, counted with multiplicity.

CONTINUANT transform of {phi(n)}, 1, 1, 2, 2, 4, 2, .. (A002088).

Number of self-avoiding walks of length n from origin in strip Z X {0,1}.

Number of self-avoiding closed walks from 0 of area n in strip Z X {-1,0,1}.

Number of self-avoiding closed walks from 0 of area n in strip Z X {0,1,2}.

Primes with indices that are primes with prime indices.

Absolute value of first differences of A038552, divided by 24.

Numbers k such that sum of the first k primes is a palindrome.

Palindromes that are the sum of consecutive initial primes.

Primes p such that the sum of the primes from 2 through p is a palindrome.

Write n in binary, delete 0's.

Write n in ternary then sort the digits.

Sizes of successive clusters in hexagonal lattice A_2 centered at deep hole.

Sizes of clusters in hexagonal lattice A_2 centered at deep hole.

Sizes of successive clusters in hexagonal lattice A_2 centered at lattice point.

Sizes of clusters in hexagonal lattice A_2 centered at lattice point.

Sizes of clusters in hexagonal lattice A_2 with 3-fold symmetry.

Number of cubefree self avoiding walks in 2 dimensions of length n.

Differences between positive cubes in 1, 2 or 3 ways: union of A014439, A014440 and A014441.

Numbers n such that n and n+1 are differences between 2 positive cubes in at least one way.

Numbers n such that n and n-1 are differences between 2 positive cubes in at least one way.

Squares that are a difference between 2 positive cubes.

Numbers whose square is a difference between 2 positive cubes in at least one way.

First differences between numbers that are a difference between 2 positive cubes.

Numbers k such that k^3 - 2 is prime.

Primes of the form n^3 - 2.

Prime numbers p such that the number of partitions of p is also a prime.

One half of convolution of central binomial coefficients A000984(n) with A000984(n+2), n >= 0.

Primes not containing the digit '1'.

Primes not containing the digit '2'.

a(n) = floor( prime(n)/n ).

Least k such that k-th prime > n * k.

a(n) is the smallest prime number k such that k > n*pi(k), where pi(k) denotes the prime counting function.

a(n) = n*(-1)^n.

Numbers that are the sum of 2 different primes.

Least common multiple of integers less than and prime to n.