6 added 361 characters in body edited May 22 '18 at 10:56 Glorfindel 17.5k55 gold badges6464 silver badges9898 bronze badges Here's an attempt for 1x4: 11x5 = 55 squares and another one for 1x5: 10x6 = 60 squares and one for 1x9: 14x14 = 196 and one for 1x10, smaller than the generalized 1x5k solution: 12x15 = 180 and one for 1x11; it looks like this sequence is somehow generalizable as well. N has a nice shape, it seems. 13x18 = 234 1x12: 18x16 = 288 Here is the minimal solution for $$2 \times 7$$, which generalizes to $$2 \times (10k + 7)$$ and is just a little bit smaller than the one discovered by Jaap: 15x15 = 255 (generalized: $$(20k + 15) \times (20k + 15)$$) Here's an attempt for 1x4: 11x5 = 55 squares and another one for 1x5: 10x6 = 60 squares and one for 1x9: 14x14 = 196 and one for 1x10, smaller than the generalized 1x5k solution: 12x15 = 180 and one for 1x11; it looks like this sequence is somehow generalizable as well. N has a nice shape, it seems. 13x18 = 234 1x12: 18x16 = 288 Here's an attempt for 1x4: 11x5 = 55 squares and another one for 1x5: 10x6 = 60 squares and one for 1x9: 14x14 = 196 and one for 1x10, smaller than the generalized 1x5k solution: 12x15 = 180 and one for 1x11; it looks like this sequence is somehow generalizable as well. N has a nice shape, it seems. 13x18 = 234 1x12: 18x16 = 288 Here is the minimal solution for $$2 \times 7$$, which generalizes to $$2 \times (10k + 7)$$ and is just a little bit smaller than the one discovered by Jaap: 15x15 = 255 (generalized: $$(20k + 15) \times (20k + 15)$$) 5 added 170 characters in body edited May 8 '18 at 10:45 Glorfindel 17.5k55 gold badges6464 silver badges9898 bronze badges Here's an attempt for 1x4: 11x5 = 55 squares and another one for 1x5: 10x6 = 60 squares and one for 1x9: 14x14 = 196 and one for 1x10, smaller than the generalized 1x5k solution: 12x15 = 180 and one for 1x11; it looks like this sequence is somehow generalizable as well. N has a nice shape, it seems. 13x18 = 234 1x12: 18x16 = 288 Here's an attempt for 1x4: 11x5 = 55 squares and another one for 1x5: 10x6 = 60 squares and one for 1x9: 14x14 = 196 and one for 1x10, smaller than the generalized 1x5k solution: 12x15 = 180 and one for 1x11; it looks like this sequence is somehow generalizable as well. N has a nice shape, it seems. 13x18 = 234 Here's an attempt for 1x4: 11x5 = 55 squares and another one for 1x5: 10x6 = 60 squares and one for 1x9: 14x14 = 196 and one for 1x10, smaller than the generalized 1x5k solution: 12x15 = 180 and one for 1x11; it looks like this sequence is somehow generalizable as well. N has a nice shape, it seems. 13x18 = 234 1x12: 18x16 = 288 4 added 227 characters in body edited May 8 '18 at 8:15 Glorfindel 17.5k55 gold badges6464 silver badges9898 bronze badges Here's an attempt for 1x4: 11x5 = 55 squares and another one for 1x5: 10x6 = 60 squares and one for 1x9: 14x14 = 196 and one for 1x10, smaller than the generalized 1x5k solution: 12x15 = 180 and one for 1x11; it looks like this sequence is somehow generalizable as well. N has a nice shape, it seems. 13x18 = 234 Here's an attempt for 1x4: 11x5 = 55 squares and another one for 1x5: 10x6 = 60 squares and one for 1x9: 14x14 = 196 and one for 1x10, smaller than the generalized 1x5k solution: 12x15 = 180 Here's an attempt for 1x4: 11x5 = 55 squares and another one for 1x5: 10x6 = 60 squares and one for 1x9: 14x14 = 196 and one for 1x10, smaller than the generalized 1x5k solution: 12x15 = 180 and one for 1x11; it looks like this sequence is somehow generalizable as well. N has a nice shape, it seems. 13x18 = 234 3 added 179 characters in body edited May 8 '18 at 7:51 Glorfindel 17.5k55 gold badges6464 silver badges9898 bronze badges 2 added 134 characters in body edited May 8 '18 at 7:33 Glorfindel 17.5k55 gold badges6464 silver badges9898 bronze badges 1 answered Apr 23 '18 at 15:22 Glorfindel 17.5k55 gold badges6464 silver badges9898 bronze badges