An 18-day solution - Kindergarten problem

(found by Warwick Harvey 2005.8.29)

[9,1,11], [10,2,12], [15,7,17], [16,8,18], [21,13,23], [22,14,24], [27,19,29], [28,20,30], [3,25,5], [4,26,6]
[7,3,11], [8,4,12], [13,9,17], [14,10,18], [19,15,23], [20,16,24], [25,21,29], [26,22,30], [1,27,5], [2,28,6]
[7,5,9], [8,6,10], [13,11,15], [14,12,16], [19,17,21], [20,18,22], [25,23,27], [26,24,28], [1,29,3], [2,30,4]
[15,1,17], [16,2,18], [21,7,23], [22,8,24], [27,13,29], [28,14,30], [3,19,5], [4,20,6], [9,25,11], [10,26,12]
[13,3,17], [14,4,18], [19,9,23], [20,10,24], [25,15,29], [26,16,30], [1,21,5], [2,22,6], [7,27,11], [8,28,12]
[13,5,15], [14,6,16], [19,11,21], [20,12,22], [25,17,27], [26,18,28], [1,23,3], [2,24,4], [7,29,9], [8,30,10]
[7,1,13], [8,2,14], [15,9,21], [16,10,22], [23,17,29], [24,18,30], [19,25,27], [20,26,28], [3,5,11], [4,6,12]
[7,13,19], [8,14,20], [15,21,27], [16,22,28], [17,5,23], [18,6,24], [1,25,29], [2,26,30], [3,9,11], [4,10,12]
[19,7,25], [20,8,26], [9,27,15], [10,28,16], [5,29,23], [6,30,24], [1,3,21], [2,4,22], [11,17,13], [12,18,14]
[10,1,12], [9,2,11], [16,7,18], [15,8,17], [22,13,24], [21,14,23], [28,19,30], [27,20,29], [4,25,6], [3,26,5]
[8,3,12], [7,4,11], [14,9,18], [13,10,17], [20,15,24], [19,16,23], [26,21,30], [25,22,29], [2,27,6], [1,28,5]
[8,5,10], [7,6,9], [14,11,16], [13,12,15], [20,17,22], [19,18,21], [26,23,28], [25,24,27], [2,29,4], [1,30,3]
[16,1,18], [15,2,17], [22,7,24], [21,8,23], [28,13,30], [27,14,29], [4,19,6], [3,20,5], [10,25,12], [9,26,11]
[14,3,18], [13,4,17], [20,9,24], [19,10,23], [26,15,30], [25,16,29], [2,21,6], [1,22,5], [8,27,12], [7,28,11]
[14,5,16], [13,6,15], [20,11,22], [19,12,21], [26,17,28], [25,18,27], [2,23,4], [1,24,3], [8,29,10], [7,30,9]
[8,1,14], [7,2,13], [16,9,22], [15,10,21], [24,17,30], [23,18,29], [20,25,28], [19,26,27], [4,5,12], [3,6,11]
[8,13,20], [7,14,19], [16,21,28], [15,22,27], [18,5,24], [17,6,23], [2,25,30], [1,26,29], [4,9,12], [3,10,11]
[20,7,26], [19,8,25], [10,27,16], [9,28,15], [6,29,24], [5,30,23], [2,3,22], [1,4,21], [12,17,14], [11,18,13]