x² a₁₃ ∫ ∈ ∃ ⊆ ≣ ℝ ∪ ⋂

GREEK ALPHABET Α Β Γ Δ Ε Ζ Η Θ Ι Κ Λ Μ Ν Ξ Ο Π Ρ Σ Τ Υ Φ Χ Ψ Ω Ϊ

greek alphabet α β γ δ ε ζ η θ ι κ λ μ ν ξ ο π ρ ς σ τ υ φ χ ψ ω ϑ ϒ ϖ

π • … ′ ″ ‾ ⁄ ¡ ¢ £ ¤ ¥ ¦ § ¨ © ª « ¬ ­ ® ¯ ° ± ² ³ ´ µ ¶ · ¸ ¹ º » [ ] { } | ¦

⁐ ⁉ ⁔ ⁚ ℵ ℘ ′ ℝ ℂ ℕ ℙ ℚ ℤ

Assorted arrows, etc. ← → ↓ ↑ ↔ ↵ ⇐ ⇑ ⇒ ⇓ ⇔ ‾ ← → ↑ ↓ † ‡ • … ✔

∀ ∂ ∃ ∅ ∄ ∇ ∈ ∉ ∋ ∌ ∍ ∏ ¬

∑ ∗ √ ∝ ∞ ∠ ∧ ⊻ ⊼ ⊽ ∨ ∩ ∪ ∫ ∴ ∼

< > ≅ ≈ ≠ ≡ ≤ ≥ ⊂ ⊃ ⊄ ⊅ ⊈ ⊉ ⊊ ⊋ ⋄ ⊆ ⊇ ⊕ ⊗ ⊝ ⋅

Superscripts ⁰ ⁱ ^{2 3} ⁲ ⁳ ⁴ ⁵ ⁶ ⁷ ⁸ ⁹ ⁺ ⁻ ⁼ ⁽ ⁾ ⁿ ⁱ ¹ ² ³

Subscripts ₀ ₁ ₂ ₃ ₄ ₅ ₆ ₇ ₈ ₉ ₊ ₋ ₌ ₍ ₎ ₏ ₐ ₑ ₒ ₓ ₔ ₕ ₖ ₗ ₘ ₙ ₚ ₛ ₜ _{i j k}

Fractions ¼ ½ ¾ Or imitate a fraction by using a superscript integer ⁄ subscript integer - e.g. ³⁄₁₉
(Note that &frasl; was used as the slash, not the regular / because it's tilted a bit more to the horizontal.)

ᵢ ᵣ ᵤ ᵥ ₓ ᵥ ᵦ ᵧ ᵨ ᵩ ᵪ

⌈ ⌉ ⌊ ⌋ ⊤ ⊥ ⊦ ⊧ ⊨ ⊩ ⊪ ⊫ ⊬ ⊭ ⊮ ⊯ ⊰ ⊱ ⊲ ⊳ ⊴ ⊵ ⊶ ⊷ ⊸ ⊹ ⊺ ⊻ ⊼ ⊽ ⊾ ⊿ ⋀ ⋁ ⋂ ⋃ ⋄ ⋅ ⋆ 〈 〉 ◊ ♠ ♣ ♥ ♦

x̄ x̂ ° µ ‰ ‱ ′ ∫ ∂ ∆ ∇ ∬ ∭ ⨌ ∮ ∯ ∰ ∱ ∲ ⨑ ∳ ℘

Non-Math

♀ ♂ ☈ ♠ ♡ ♢ ♣ ¢

Modified characters ᵃ ᵄ ᵅ ᵆ ᵇ ᵈ ᵉ ᵋ ᵍ ᵎ ᵏ ᵐ ᵑ ᵒ ᵓ ᵔ ᵕ ᵖ ᵗ ᵘ ᵙ ᵚ ᵛ ᵜ ᵝ ᵞ ᵟ ᵠ ᵡ ᵸ ᶛ ᶜ ᶝ ᶞ ᶟ ᶠ ᶡ ᶢ ᶣ ᶤ ᶥ ᶦ ᶧ ᶨ ᶩ ᶪ ᶫ ᶬ ᶭ ᶮ ᶯ ᶰ ᶱ ᶲ ᶳ ᶴ ᶵ ᶶ ᶷ ᶸ ᶹ ᶺ ᶻ ᶼ ᶽ ᶾ ᶿ

Another list of mathematical symbols

Yet another list

One more

Statistical Symbols

Mathematical Symbols a presentation of many math symbols with very brief mention of where they are used and what they mean. Not for copy/paste - but this could be helpful.

Superscript and subscript letters