Lucas Sequence
Defined with \(L_0=2\), \(L_1=1\), and \(L_n=L_{n-1}+L_{n-2}\) when \(n\geq2\). Related to the Fibonacci sequence.
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
| 645: | \[L_{645}\] | 22 × 11 × 31 × 431 × 1291 × 1721 × 6709 × 144481 × 308311 × 2564521 × 17861341 × 691419023311<12> × 761882591401<12> × 1266715025281<13> × 66163448516461<14> × 497882131309853461<18> × 1594403967069207665025028111<28> |