Sequences

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

PDan numbers: numbers n of the form 3^A * 5^B * 7^C * 11^D with n+-2 and n+-4 prime.

Theta series of 6-dimensional 8-modular lattice of minimal norm 4.

a(n) = Sum_{k divides 3^n} S(k), where S is the Kempner function A002034.

a(n) = Sum_{k divides 2^n} S(k), where S is the Kempner function A002034.

Partial sums of Kempner numbers A002034.

First differences of Kempner numbers A002034.

Numbers of form 2x^2 + 2xy + 3y^2.

Theta series of odd 8-dimensional 5-modular lattice O(5).

Theta series of 8-dimensional strongly 6-modular lattice O(6) with minimal norm 3.

Theta series of 6-dimensional extremal 5-modular lattice Q6(4)^{+2}.

Smallest positive integer containing the n-th letter of the alphabet (in US English), or -1 if no such integer exists.

Trace of Frobenius of the reduction mod 2 of the elliptic curve C / L, L a lattice with Gram matrix [ 4 1; 1 2n ].

Odd numbers congruent to 7 mod 8 such that (2^(h(-n)+2)-n) is a square, where h(-n) is the class number.

Number of distinct subgroups of alternating group A_n, counting conjugates as distinct.

Number of conjugacy classes of subgroups of the alternating group A_n.

Complete list of solutions to y^2 = x^3 + 17; sequence gives y values.

Complete list of solutions to y^2 = x^3 + 17; sequence gives x values.

Degree of the variety of pairs of commuting n X n matrices.

Numbers that are palindromic in base 16.

Palindromic in bases 10 and 16.

Palindromic primes in base 16 (or hexadecimal), but written here in base 10.

Numbers k such that k^2 is palindromic in base 16.

Palindromic squares in base 16.

Numbers k such that k^3 is palindromic in base 16.

Palindromic cubes in base 16.

Numbers whose square is palindromic in base 12.

Palindromic squares in base 12.

Numbers that are congruent to {1, 3, 4} mod 6.

Odd numbers with distinct digits.

Even numbers with distinct digits.

Nonpalindromic numbers.

Primes with distinct digits.

Numbers of the form 2^n or 3*2^n.

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

Numbers of the form 2^k or 7*2^k.

Numbers of the form 2^k times 1, 3 or 5.

Numbers of the form 2^k times 1, 3 or 7.

Numbers of the form 2^k times 1, 5 or 7.

List of numbers of the form 2^k times 1, 3, 5 or 7.

Average theta series of odd unimodular lattices in dimension 12.

Theta series of any of the 5 extremal odd unimodular 32-dimensional lattices (with minimal norm 4).

Theta series of shadow of any of the 5 extremal odd unimodular 32-dimensional lattices (with minimal norm 4).

Theta series of shadow of shorter Leech lattice.

Smallest dimension in which a unimodular lattice of minimal norm n occurs.

Smallest dimension in which a strictly odd unimodular lattice of minimal norm n occurs.

a(n) = 5^n mod 2^n.

Number of AVL trees of height n.

Number of permutations which are the union of an increasing and a decreasing subsequence.

A sum with next-to-central binomial coefficients of even order, Catalan related.