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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 2 |
| 3 | 4 |
| 4 | 13 |
| 5 | 36 |
| 6 | 115 |
| 7 | 342 |
| 8 | 1139 |
| 9 | 3764 |
| 10 | 12958 |
| 11 | 44395 |
| 12 | 155181 |
| 13 | 549379 |
| 14 | 1971824 |
| 15 | 7110201 |
| 16 | 25895872 |
| 17 | 94857236 |
| 18 | 350624428 |
| 19 | 1302239497 |
| 20 | 4858414337 |
| 21 | 18230049290 |
| 22 | 68700089837 |
| 23 | 260092887599 |
| 24 | 988164427994 |
| 25 | 3765690820956 |
| 26 | 14407647305594 |
| 27 | 55282778658419 |
| 28 | 212749959207908 |
| 29 | 820917116037383 |
| 30 | 3174828575276883 |
[1,1,2,4,13,36,115,342,1139,3764,12958,44395, 155181,549379,1971824,7110201,25895872,94857236, 350624428,1302239497,4858414337,18230049290, 68700089837,260092887599,988164427994, 3765690820956,14407647305594,55282778658419, 212749959207908,820917116037383,3174828575276883] |