Sequences

Alkane (or paraffin) numbers l(10,n).

Alkane (or paraffin) numbers l(11,n).

Alkane (or paraffin) numbers l(12,n).

Alkane (or paraffin) numbers l(13,n).

a(n) = n*4^n.

Maximal number of subgroups in a group with n elements.

Sum(C(j)*(n-j)*4^(n-j),j=0..n-1), C = Catalan numbers.

Sum(C(j)*(n-j)*4^(n-j-1),j=0..n-1), C = Catalan numbers.

Table T(a,b) by antidiagonals of winning positions in 3-pile Wythoff game (a square array).

Row 1 of A018219, i.e., (1, n, a_n) is a winning position.

Row 2 of A018219, i.e., (2,n,a_n) is a winning position.

Row 3 of A018219, i.e., (3,n,a_n) is a winning position.

Number of 5-voter voting schemes with n linearly ranked choices.

a(n) = binomial(n, floor(n/2))^2 = A001405(n)^2.

Number of connected chord diagrams of degree n.

Magic numbers of nucleons: nuclei with one of these numbers of either protons or neutrons are more stable against nuclear decay.

Magic numbers: atoms with full shells containing any of these numbers of electrons are considered electronically stable.

Numbers k such that normalizer of Gamma_0(k) is triangle group (2,3,inf).

Numbers k such that normalizer of Gamma_0(k) is triangle group (2,4,inf).

Numbers k such that normalizer of Gamma_0(k) is triangle group (2,6,inf).

Numbers k such that normalizer of Gamma_0(k) is a triangle group.

Consider pairs (k,m) such that k^2 begins with a 1 and when the 1 is changed to a 2 we again get a square, m^2; sequence gives values of m for primitive solutions.

Consider pairs (k,m) such that k^2 begins with a 1 and when the 1 is changed to a 2 we again get a square, m^2; sequence gives values of k for primitive solutions.

Theta series of 52-dimensional lattice of det 2^26 and minimal norm 3.

Weight distribution of (48,2^24,12) binary code obtained from Golay code of length 24 lifted to Z/4Z and mapped to GF(2)^2.

Weight distribution of hypothetical [ 72,36,16 ] doubly-even binary self-dual code.

Weight distribution of hypothetical [ 68,34,12 ] code derived from hypothetical [ 72,36,16 ] doubly-even self-dual code.

Add 1 to leading digit and put in front.

Primorial primes: primes of the form 1 + product of first k primes, for some k.

Number of rational knots (or two-bridge knots) with n crossings (up to mirroring).

Number of simple allowable sequences on 1..n.

Number of projective order types.

Inverse Euler transform of A000931.

A self-generating sequence: there are a(n) (k+1)'s between successive k's, where k=3.

A self-generating sequence: there are a(n) (k+1)'s between successive k's, where k=4.

A self-generating sequence: there are a(n) (k+1)'s between successive k's, where k=5.

The 10-adic integer x = ...8212890625 satisfying x^2 = x.

The 10-adic integer x = ...1787109376 satisfies x^2 = x.

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

Expansion of 1/((1-4x)(1-5x)(1-8x)).

Divisors of 18.

The nonprime numbers: 1 together with the composite numbers, A002808.

Divisors of 24.

Divisors of 28.

Divisors of 30.

Divisors of 36.

Divisors of 40.

Divisors of 42.

Divisors of 44.

Divisors of 45.