j. 4
0j4

   3 j. 4
3j4

   a=: i. 3 3
   a;(j. 2*a);(a j. 2*a)
+-----+--------------+--------------+
|0 1 2|   0  0j2  0j4|   0  1j2  2j4|
|3 4 5| 0j6  0j8 0j10| 3j6  4j8 5j10|
|6 7 8|0j12 0j14 0j16|6j12 7j14 8j16|
+-----+--------------+--------------+

   (+ a j. 2*a);(|a j. 2*a)
+-----------------+-----------------------+
|    0  1j_2  2j_4|      0 2.23607 4.47214|
| 3j_6  4j_8 5j_10| 6.7082 8.94427 11.1803|
|6j_12 7j_14 8j_16|13.4164 15.6525 17.8885|
+-----------------+-----------------------+

   1 2 3 j./ 4 5 6 7
1j4 1j5 1j6 1j7
2j4 2j5 2j6 2j7
3j4 3j5 3j6 3j7

   j./?. 2 3 4$1000            隨機複數表
 131j34  755j53 458j529 532j671
  218j7  47j383  678j66 679j417
934j686 383j588 519j930 830j846