%I A098501
%S A098501 1,2,5,13,31,49,70,93,121,151,186,223,265,309,358,409,465,523,586,651,
%T A098501 721,793,870,949,1033,1119,1210,1303,1401,1501,1606,1713,1825,1939,2058,
%U A098501 2179,2305,2433,2566,2701,2841,2983,3130,3279,3433,3589,3750
%N A098501 Number of squares on infinite octant of chessboard at <=n knight moves 
               from the corner. The octant includes the diagonal.
%F A098501 (1/8) [14n^2 + 8n + 5 + 3(-1)^n], for n>4.
%e A098501 2 squares are reachable after 1 move, from these you can reach 3 new 
               squares more, so a(1)=2, a(2)=5.
%Y A098501 See A018836 (unbounded), A098498 (halfplane), A098499 (diagonal halfplane), 
               A098500 (quadrant).
%Y A098501 Sequence in context: A065377 A077278 A073683 this_sequence A116701 A068739 
               A063636
%Y A098501 Adjacent sequences: A098498 A098499 A098500 this_sequence A098502 A098503 
               A098504
%K A098501 nonn
%O A098501 0,2
%A A098501 Ralf Stephan (ralf(AT)ark.in-berlin.de), Sep 15 2004