There exists another "Boustrophedon"-sequence in OEIS. I like the name "Boustrophedon primes" and appreciate all the work that was done in a short time for A330339. What I do not like is that Boustrophedon primes can only occur on the left ends of the lines and never on the right ends (except of the prime 2). Therefore I thought about a slightly different definition and found another "Boustrophedon"-sequence which already exists in OEIS. In the following graphic all primes are represented by colored dots and all other natural numbers by small black dots. https://www.trump.de/definition-A330339-A282178.gif Neil already added in the description of A282178 a link to A330339. A big b-file with the first 846 elements already exists. A282178 was created by Samuel B. Reid in 2017. A282178 starts with number 1 and has a higher density than A330339. Please have a look at 3 pictures demonstrating A282178. !!! Zoom in to read all primes !!! https://www.trump.de/A282178-01.gif https://www.trump.de/A282178-02.gif Especially I like the definition using a perfect zigzag path of the natural numbers with primes in the vertices of the path: https://www.trump.de/A282178-zigzag.gif Walter