2,1

Worthy of consideration to introduce slopes in the math classroom.

a(7) >= 23 and a(8) >= 29, see illustration in Links.

Table of n, a(n) for n=2..6.

Hiroaki Yamanouchi, Examples

Giovanni Resta, Illustration of a(7)>=23 and a(8)>=29

a(3) = 5 because of this quadrilateral in a 3 x 3 square:

1 2 .

. 4 .

5 . 3

a(4) = 8 because of this polygon:

1 3 . 4

. . 2 6

. . 5 7

. 8 . .

Cf. A271449. Construction perhaps related to construction of Costas arrays: A008404.

Sequence in context: A094913 A265060 A320849 * A020678 A310034 A014811

Adjacent sequences: A255978 A255979 A255980 * A255982 A255983 A255984

nonn,more

Gordon Hamilton, Mar 13 2015

a(5)-a(6) corrected by Hiroaki Yamanouchi, Mar 14 2015

approved