User:Douglas de Araujo Smigly

I am a math student interested in Number Theory and Algebra, specially sequences such as Fibonacci, Lucas, Pell numbers and Prime numbers.

Sequence of the Day [talk] Sequence of the Day for March 12 A066680: Badly sieved numbers: as in the sieve of Eratosthenes, multiples of unmarked numbers p are marked, but only up to p 2 . { 2, 3, 5, 7, 8, 11, 12, 13, 17, 18, 19, 23, 27, 29, ... } So 6 gets culled out not for being an even number but for being a multiple of 3 less than 9; and 12 gets to stay because it is greater than both 4 and 9, and not a multiple of 5, 7 or 11. Selected Recent Additions A239797 Decimal expansion of ${\frac {\sqrt {3}}{\sqrt[{3}]{4}}}$. A238271 Decimal expansion of $\sum _{n=1}^{\infty }{\frac {\mu (n)}{3^{n}}}$. A237042 UPC check digits. A236603 Lowest canonical Gray cycles of length $2n$. A235365 Smallest odd prime factor of $3^{n}+1$. A234522 Decimal expansion of ${\sqrt[{4}]{7}}-{\sqrt[{4}]{5}}$. A233748 Number of graphs on n vertices with edges colored with at most four interchangeable colors under the symmetries of the full edge permutation group. A232499 Number of unit squares, aligned with a Cartesian grid, completely within the first quadrant of a circle centered at the origin ordered by increasing radius. A231963 Concatenate $n$ with its UPC check digit. A230624 Numbers $n$ with property that for every base $b\geq 2$, there is a number $m$ such that $m+s(m)=n$, where $s(m)$ is the sum of digits in the base $b$ expansion of $m$.

Sequences in the News Aug 17 2021 Swiss scientists announce they have calculated π (A000796) to 62.8 trillion digits in only 108 days. Dec 25 2018 German Heise-News "integers, please" column explains A003173 and OEIS. Feb 01 2018 Alphabet announced a $8,589,869,056 = $A000396(6) stock buyback. Jan 03 2018 Largest known term of A000043 announced: 77232917. Nov 18 2016 PrimeGrid proves that 10223 is not a Sierpinski number, since 10223 × 2 31172165 + 1 is prime. So no changes to A076336 for now. Sep 14 2016 Tom Greer discovers the twin primes 2996863034895 × 2 1290000 ± 1 using PrimeGrid, TwinGen and LLR. Jan 19 2016 Largest known term of A000043 announced: 74207281, also discovered by Curtis Cooper.

$e^{i\pi }+1=0$