In Pingala's Chandahsutra (~200 BCE), four short aphorisms describe a recursive algorithm: halve the number, double when zero, square when halved, subtract one when odd. The output is 2ⁿ for n syllables of a Sanskrit metre. Leibniz publishes binary arithmetic in 1703. Modern exponentiation-by-squaring (the cryptographic core of every TLS handshake) follows the same recurrence. Pingala wrote it down 1,900 years earlier, for poetic prosody.