The Fibonacci sequence is named after Italian mathematician Leonardo of Pisa, known as Fibonacci. His 1202 book Liber Abaci introduced the sequence to Western European mathematics,[6] although the sequence had been described earlier as Virahanka numbers in Indian mathematics.[7][8][9] By modern convention, the sequence begins either with F0 = 0 or with F1 = 1. The sequence described in Liber Abaci began with F1 = 1.