The story
After its two independent discoverers, Edmund Landau and Srinivasa Ramanujan.
Etymology from Wiktionary, CC BY-SA 4.0.
Landau-Ramanujan constant
Today it means: The constant of proportionality (approximately 0.7642) in the relationship between the number of positive integers less than x that are the sum of two square numbers, for large x, and the expression x/√(ln (x)). Full definition →