Sequences

Partial sums of primes congruent to 5 mod 6.

Two different numbers a, b which satisfy sigma(a)=sigma(b)=(a+b)^3/(a^2+b^2) are called a rational amicable pair; sequence gives a numbers.

Two different numbers a, b which satisfy sigma(a)=sigma(b)=(a+b)^3/(a^2+b^2) are called a rational amicable pair; sequence gives b numbers.

Numbers n such that n = (product of digits of n) + (sum of digits of n).

Numbers n with property that digits of n are not present in 2n.

n is divisible by (product of digits) + (sum of digits).

Numbers n with property that (product of digits of n) is divisible by (sum of digits of n).

n is divisible by |(product of digits) - (sum of digits)|.

Numbers k such that k = (product of digits of k) * (sum of digits of k).

Smallest prime with "n^2" as central digit(s).

Smallest prime factor of 10^n + 1.

Largest subset of integers [ 1...n ] such that no member divides two others.

Number of n-step self-avoiding paths on quadrant grid starting at quadrant origin.

Length of longest contiguous block of 1's in binary expansion of n.

Maximal number of spanning paths in a tournament on n nodes.

a(n) = (n-3)*A006918(n-2)/2 for n >= 2, with a(0) = a(1) = 0.

Number of odd nonprimes <= (2n+1)^2.

Integers which have more distinct digits than any smaller number.

Number of real {0,1} n X n matrices A such that M = A + A' has 2's on the main diagonal, 0's and 1's elsewhere and is positive semi-definite.

Number of perifusenes with one internal vertex.

Number of perifusenes with one internal vertex and symmetry point group C_s.

Number of perifusenes with one internal vertex.

Number of perifusenes with one internal vertex.

Number of perifusenes with one internal vertex.

Number of perifusenes with one internal vertex.

Number of "connected animals" formed from n 4-gon or 6-gon connected truncated octahedra in the b.c.c. lattice, allowing only translation of the lattice.

a(n) is the smallest number such that the arithmetic mean (A) and geometric mean (G) of n and a(n) are both integers.

Let f(n) be the smallest number such that the arithmetic mean (A) and geometric mean (G) of n and f(n) are both integers; sequence gives G values.

Let f(n) be the smallest number such that the arithmetic mean (A) and geometric mean (G) of n and f(n) are both integers; sequence gives A values.

Bisection of A028289.

Expansion of (x^3+2*x+1) / ((x-1)^4*(x^2+x+1)^2).

Number of mono-4-polyhexes with n cells.

Number of 4n-step self-avoiding closed paths on first quadrant grid, passing through origin, symmetric about line y = x.

Concatenate first n primes in reverse order.

Concatenation of the first n odd numbers in reverse order.

Concatenate first n even numbers in reverse order.

Concatenate first n squares in reverse order.

Concatenate first n cubes in reverse order.

Concatenate first n nonzero Fibonacci numbers in reverse order.

List of pairs of consecutive numbers each with 6 divisors (duplicates removed).

Coordination sequence T3 for Zeolite Code AFN.

Coordination sequence T2 for Zeolite Code AFN.

Coordination sequence T1 for Zeolite Code AFN.

Coordination sequence T4 for Zeolite Code AFN.

Coordination sequence T3 for Zeolite Code AWO.

Coordination sequence T1 for Zeolite Code AWO.

Coordination sequence T2 for Zeolite Code AWO.

Coordination sequence for Zeolite Code DFT.

Coordination sequence T1 for Zeolite Code ESV.

Coordination sequence T2 for Zeolite Code ESV.