of positive integers is called central if for every positive integer 
, the arithmetic mean of the first 
terms of the sequence is equal to 
of positive integers such that for every central sequence 
there are infinitely many positive integers 
.
be prime numbers such that their sum isn't divisible by 
.
positive integer quadruples satisfy:
Y by Mango247
Let 
be an isosceles triangle with vertex in 
and 
. Let 
be the foot of the bisector from 
. Show that 
.
be an isosceles triangle with vertex in 
and 
. Let 
be the foot of the bisector from 
. Show that 
.This post has been edited 1 time. Last edited by parmenides51, Dec 16, 2022, 9:46 AM
