OFFSET
1,2
LINKS
Eric Weisstein's World of Mathematics, Grid Graph.
FORMULA
a(n) >= A331968(n).
EXAMPLE
a(4) = 12:
O O O O
O O
O O O
O O O
CROSSREFS
KEYWORD
nonn,more
AUTHOR
Andrew Howroyd, Feb 26 2023
STATUS
approved