OFFSET
0,15
COMMENTS
Inspired by A257594, in which the centers of circles can be considered to be placed on coordinate points of the planar net 3.3.3.3.3.3. See illustrations in the links.
LINKS
Kival Ngaokrajang, Illustration for n = 0..11, for n = 12..22
CROSSREFS
KEYWORD
nonn,more
AUTHOR
Kival Ngaokrajang, May 23 2015
STATUS
approved