Sequences

Composite numbers with smallest prime factor >= 11.

Nonprime numbers with smallest prime factor >= 13.

Numbers with three not necessarily distinct prime factors with smallest prime >=5.

Primes corresponding to A046411.

Number of self-avoiding walks on a tetrahedral (diamond) net, having 2n steps and forming a closed loop.

Total number of different legs traversed by all loops of length 2n in A038515.

Decimal expansion of Gauss-Kuzmin-Wirsing constant.

Number of elements of GF(2^n) with trace 0 and subtrace 0.

Number of elements of GF(2^n) with trace 0 and subtrace 1.

Number of elements of GF(2^n) with trace 1 and subtrace 0.

Number of elements of GF(2^n) with trace 1 and subtrace 1.

On a (2n+1) X (2n+1) board, let m(i) be the number of squares that are i knight's moves from center; sequence gives max m(i) for i >= 0.

A minimal sequence of weights with distinct weighings, with limit of two weights per pan.

Numbers k such that the k-th Fibonacci number is composite and the concatenation of its prime factors (written in base 10 in ascending order) is prime.

Numbers n with property that either the n-th Fibonacci number is prime or the concatenation of its prime factors is prime.

Concatenation of prime factors of n-th Fibonacci number.

Same as A038528, except you may rearrange the digits before applying f; sequence gives n such that f(f(f(...(n)))) = 0 or empty.

If n has decimal expansion abc...d, with k digits, let f(n) be obtained by deleting all k's from abc...d, closing up and deleting initial 0's; sequence gives n such that f(f(f(...(n)))) = 0 or empty.

n-th prime - n-th composite.

Concatenate n-th prime and n-th composite.

Primes that are concatenations of k-th prime and k-th composite.

Primes that are concatenations of k-th composite and k-th prime.

Denominator of coefficients of both EllipticK/Pi and EllipticE/Pi.

Numerators of coefficients of EllipticK/Pi.

Numerators of coefficients of EllipticE/Pi.

Odd values of k > 1 for which there are k-hyperperfect numbers.

Primes base 10 that remain primes in eight bases b, 2<=b<=10, when the expansions are interpreted as decimal numbers.

Number of semisimple rings with n elements.

Complex semisimple Lie algebras of dimension n.

a(n) = number of modules with n elements over the ring of integers in the real quadratic field of discriminant 40.

a(n) = number of modules with n elements over the ring of integers in the imaginary quadratic field of discriminant -20.

Primes p such that Ramanujan function tau(p) is divisible by 11.

Primes p such that Ramanujan function tau(p) is divisible by 13.

a(n) = Sum_{i=0..10^n} i^3.

a(n) = Sum_{i=0..10^n} i^10.

Numbers n such that n-th Fibonacci number has initial digits n.

Least number with exactly n odd divisors.

Number of divisors of n that are at most sqrt(n).

Least number with exactly n divisors that are at most its square root.

Products of an odd prime and a power of two (sorted).

First differences of A003173.

Largest squarefree number k such that Q(sqrt(-k)) has class number n.

Maximum cycle length in differentiation digraph for n-bit binary sequences.

Derivative of n: write n in binary, replace each pair of adjacent bits with their mod 2 sum (a(0)=a(1)=0 by convention). Also n XOR (n shift 1).

Derivative of n in base 3.

Periodic derivative of n.

Periodic derivative of n in base 3.

Smallest number with derivative n.

a(n) = 2*A040027(n-1) + Bell(n), where Bell = A000110.

Binomial recurrence coefficients.