OFFSET
1,1
LINKS
Dimitri Tishchenko, Hexagon Prime Spiral
EXAMPLE
The spiral begins
13--12--11
/ \
14 4---3 10
/ / \ \
15 5 1---2 9
\ \ /
16 6---7---8
\
17--18--19--...
For n=4, prime(4) = 7 in the spiral has a(4) = 2 primes adjacent (2 and 19).
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Wade Reece Eberly, Sep 23 2022
STATUS
approved