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| n | a(n) |
|---|---|
| 1 | 4 |
| 2 | 15 |
| 3 | 48 |
| 4 | 118 |
| 5 | 254 |
| 6 | 498 |
| 7 | 916 |
| 8 | 1605 |
| 9 | 2702 |
| 10 | 4395 |
| 11 | 6936 |
| 12 | 10656 |
| 13 | 15982 |
| 14 | 23456 |
| 15 | 33756 |
| 16 | 47719 |
| 17 | 66366 |
| 18 | 90929 |
| 19 | 122880 |
| 20 | 163962 |
| 21 | 216222 |
| 22 | 282046 |
| 23 | 364196 |
| 24 | 465849 |
| 25 | 590638 |
| 26 | 742695 |
| 27 | 926696 |
| 28 | 1147908 |
| 29 | 1412238 |
| 30 | 1726284 |
| 31 | 2097388 |
| 32 | 2533691 |
| 33 | 3044190 |
| 34 | 3638797 |
[4,15,48,118,254,498,916,1605,2702,4395,6936, 10656,15982,23456,33756,47719,66366,90929,122880, 163962,216222,282046,364196,465849,590638,742695, 926696,1147908,1412238,1726284,2097388,2533691, 3044190,3638797] |