Sequences

Theta series of quadratic form (or lattice) with Gram matrix [ 3, 1; 1, 8 ].

Numbers represented by quadratic form with Gram matrix [ 2, 1, 0; 1, 3, 1; 0, 1, 5 ].

Theta series of quadratic form with Gram matrix [ 2, 1, 0; 1, 3, 1; 0, 1, 5 ].

Numbers represented by quadratic form with Gram matrix [ 2, 1, 1; 1, 4, 2; 1, 2, 4 ], divided by 2.

Six consecutive integers with increasing values of sigma start at these numbers; i.e., sigma(x) < sigma(x+1) < ... < sigma(x+5).

Norms of vectors in the a.c.c. lattice, divided by 2.

Theta series of a.c.c. lattice.

Numbers represented by quadratic form with Gram matrix [ 2, 1, 1; 1, 2, 1; 1, 1, 3 ].

Duplicate of A029681.

Numbers represented by quadratic form with Gram matrix [ 3, 1, 1; 1, 3, 1; 1, 1, 3 ].

Theta series of quadratic form with Gram matrix [ 3, 1, 1; 1, 3, 1; 1, 1, 3 ].

Numbers represented by quadratic form with Gram matrix [ 7, 1, -3; 1, 3, 1; -3, 1, 7 ].

Theta series of quadratic form with Gram matrix [ 7, 1, -3; 1, 3, 1; -3, 1, 7 ].

Numbers represented by quadratic form with Gram matrix [ 3, 1, 0; 1, 3, 1; 0, 1, 3 ].

Theta series of quadratic form with Gram matrix [ 3, 1, 0; 1, 3, 1; 0, 1, 3 ].

Theta series of 8-d 5-modular lattice Q_8(1) with det 625 and minimal norm 4.

Theta series of 8-d 6-modular lattice G_2 tensor F_4 (or A_2 tensor D_4) with det 1296 and minimal norm 4 in powers of q^2.

Product of prime and previous prime is palindromic.

Palindromes which are the product of two consecutive primes.

Numbers whose sum of divisors is palindromic.

Primes p such that p+1 is palindromic.

Squares and twice squares.

Numbers whose sum of divisors is even.

Palindromes whose sum of divisors is odd.

Nonsquare palindromes whose sum of divisors is odd.

Palindromes whose sum of divisors is palindromic.

Repdigit - 1 is prime.

Repdigit + 1 is prime.

Smallest palindromic prime with 2n-1 digits.

Largest palindromic prime with 2n-1 digits.

Odd 9-gonal (or enneagonal) numbers.

Even 9-gonal (or enneagonal) numbers.

Odd 10-gonal (or decagonal) numbers.

Even 10-gonal (or decagonal) numbers.

Theta series of 10-d 11-modular Craig lattice A_10^(3).

Theta series of quadratic form with Gram matrix [ 4, 1, 0, 2; 1, 4, 2, 0; 0, 2, 4, -1; 2, 0, -1, 4 ].

Theta series of quadratic form with Gram matrix [ 4, 1, 0, 1; 1, 4, 1, 0; 0, 1, 4, -1; 1, 0, -1, 4 ].

Theta series of quadratic form with Gram matrix [ 4, 2, 2, 1; 2, 4, 1, 2; 2, 1, 6, 3; 1, 2, 3, 6 ].

Binary expansion of arctan(1/2)/Pi.

Expansion of 1/((1-x)*(1-x^2)*(1-x^3)*(1-x^6)).

Expansion of 1/((1-x)(1-x^2)(1-x^3)(1-x^7)).

Expansion of 1/((1-x)*(1-x^2)*(1-x^3)*(1-x^8)).

Expansion of 1/((1-x)*(1-x^2)*(1-x^3)*(1-x^9)).

Expansion of 1/((1-x)(1-x^2)(1-x^3)(1-x^10)).

Expansion of 1/((1-x)*(1-x^2)*(1-x^3)*(1-x^11)).

Expansion of 1/((1-x)*(1-x^2)*(1-x^3)*(1-x^12)).

Expansion of 1/((1-x)(1-x^2)(1-x^4)(1-x^5)).

Expansion of 1/((1-x)*(1-x^2)*(1-x^4)*(1-x^7)).

Expansion of 1/((1-x)*(1-x^2)*(1-x^4)*(1-x^9)).

Expansion of 1/((1-x)(1-x^2)(1-x^4)(1-x^11)).