New posts in Oeis

A $2021$ problem: $20\sim 21$ and $43\times 47$

The equation $\sigma(n)=\sigma(n+1)$

Why would you take the logarithmic derivative of a generating function?

Explanation of OEIS:A000236 - Residue Classes

What is the $m$th derivative of $\log\left(1+\sum\limits_{k=1}^N n_kx^k\right)$ at $x=0$?

A sequence of coefficients of $x+(x+(x+(x+(x+(x+\dots)^6)^5)^4)^3)^2$

Repeatedly taking mean values of non-empty subsets of a set: $2,\,3,\,5,\,15,\,875,\,...$

How many different functions we have by only use of $\min$ and $\max$?

Sum of digits of repunits

Simple-looking sequences $A$ and $B$ defined by a complementary equation