10 6 11 7 12 8 13
(Alternating series: x, y, x+1, y+1, x+2, y+2, ...)
1 12 3 11 5 10 7
(Alternating series: x, y, x+2, y-1, x+4, y-2, ...)
2 1 4 3 6 5 8
(Alternating series: x, y, x+2, y+2, x+4, y+4, ...)
1 2 2 4 3 6 4
(Alternating series: x, y, x+1, y+2, x+2, y+4, ...)
10 1 12 2 14 3 16
(Alternating series: x, y, x+2, y+1, x+4, y+2, ...)
20 2 40 4 60 6 80
(Alternating series: x, y, x+20, y+2, x+40, y+4, ...)
10 2 9 4 8 6 7
(Alternating series: x, y, x-1, y+2, x-2, y+4, ...)
12 10 15 11 18 12 21
(Alternating series: x, y, x+3, y+1, x+6, y+2, ...)
3 5 6 10 9 15 12
(Alternating series: x, y, x+3, y+5, x+6, y+10, ...)
1 99 2 98 3 97 4
(Alternating series: x, y, x+1, y-1, x+2, y-2, ...)
99 1 98 2 97 3 96
(Alternating series: x, y, x-1, y+1, x-2, y+2, ...)
100 5 110 10 120 15 130
(Alternating series: x, y, x+10, y+5, x+20, y+10, ...)
5 1 10 2 15 3 20
(Alternating series: x, y, x+5, y+1, x+10, y+2, ...)
88 2 87 4 86 6 85
(Alternating series: x, y, x-1, y+2, x-2, y+4, ...)
90 10 91 20 92 30 93
(Alternating series: x, y, x+1, y+10, x+2, y+20, ...)
25 100 26 200 27 300 28
(Alternating series: x, y, x+1, y+100, x+2, y+200, ...)
3 10 6 9 9 8 12
(Alternating series: x, y, x+3, y-1, x+6, y-2, ...)
4 5 8 6 12 7 16
(Alternating series: x, y, x+4, y+1, x+8, y+2, ...)
5 3 7 4 9 5 11
(Alternating series: x, y, x+2, y+1, x+4, y+2, ...)
3 12 6 24 9 36 12
(Alternating series: x, y, x+3, y+12, x+6, y+24, ...)
4 100 8 200 12 300 16
(Alternating series: x, y, x+4, y+100, x+8, y+200, ...)
1 20 3 40 5 60 7
(Alternating series: x, y, x+2, y+20, x+4, y+40, ...)
15 7 30 14 45 21 60
(Alternating series: x, y, x+15, y+7, x+30, y+14, ...)
7 11 14 22 21 33 28
(Alternating series: x, y, x+7, y+11, x+14, y+22, ...)
11 2 22 4 33 6 44
(Alternating series: x, y, x+11, y+2, x+22, y+4, ...)