Consecutive Composite Numbers
Define a list of the first $n$ prime numbers $p_1, p_2, \ldots, p_n$.
Create a set of $n$ congruences
\begin{align*} x + 1 &\equiv 0 \pmod{p_1} \\ x + 2 &\equiv 0 \pmod{p_2} \\ &\vdots \\ x + n &\equiv 0 \pmod{p_n} \end{align*}
By the Chinese Remainder Theorem (CRT), there exists a unique solution $x$.
The solution $x$ gives the start of a sequence of $n$ consecutive composite numbers:
$$x + 1, x + 2, \ldots, x + n$$
Example
Here's a C example to generate 21 consecutive composites using the above CRT method.
x+1 = 18242056294531940584645872728
x+2 = 18242056294531940584645872729
x+3 = 18242056294531940584645872730
x+4 = 18242056294531940584645872731
x+5 = 18242056294531940584645872732
x+6 = 18242056294531940584645872733
x+7 = 18242056294531940584645872734
x+8 = 18242056294531940584645872735
x+9 = 18242056294531940584645872736
x+10 = 18242056294531940584645872737
x+11 = 18242056294531940584645872738
x+12 = 18242056294531940584645872739
x+13 = 18242056294531940584645872740
x+14 = 18242056294531940584645872741
x+15 = 18242056294531940584645872742
x+16 = 18242056294531940584645872743
x+17 = 18242056294531940584645872744
x+18 = 18242056294531940584645872745
x+19 = 18242056294531940584645872746
x+20 = 18242056294531940584645872747
x+21 = 18242056294531940584645872748
Question
The common methods to generate consecutive composites are
$$\overbrace{(n+1)! + 2, \ (n+1)! + 3, \ \ldots, \ (n+1)! + (n+1)}^{\text{n composites}}$$
$$\overbrace{n!+2,n!+3,...,n!+n}^{\text{n-1 composites}}$$
$$\overbrace{n\#+2,n\#+3,âŚn\#+n}^{\text{n-1 composites (Primorials)}}$$
I'm curious what are the reasons this Chinese Remainder method to generate consecutive composite numbers
isn't as well known?
generate consecutive composites
referenced in those duplicate questions? It wasn't clear to me. Thanks. â vengy Jan 19 '24 at 20:05