2,2
a(8) >= 22, see picture in Links.
Table of n, a(n) for n=2..7.
Giovanni Resta, Illustration of a(3)-a(7) and a(8) >= 22
a(5)=9 because of this polygon on a 5 X 5 grid:
2 . . . .
. . 1 3 5
. . 4 . 7
. 6 . . 8
9 . . . .
See Links for other examples.
Cf. A255981.
Sequence in context: A127621 A049707 A213685 * A261956 A344683 A166633
Adjacent sequences: A271446 A271447 A271448 * A271450 A271451 A271452
nonn,more
Giovanni Resta, May 05 2016
approved
