Historical clue formulations

• Kind of sequence that proceeds 0, 1, 1, 2, 3, 5, 8, 13, ... — 2026-01-02
• Eponym for a mathematical pattern identified centuries earlier in India — 2021-07-02
• Like the two 40-Across in the grid for this answer — 2021-05-05
• Eponym of a number series that begins 1, 1, 2, 3, 5, 8, ... — 2014-01-27