Series and Sequence Formulas:

• Arithmetic Sequence: aₙ = a₁ + (n-1)d
• Arithmetic Series Sum: Sₙ = n(a₁ + aₙ)/2
• Geometric Sequence: aₙ = a₁rⁿ⁻¹
• Geometric Series Sum: Sₙ = a₁(1-rⁿ)/(1-r), r≠1
• General Series: ∑aₙ = a₁ + a₂ + a₃ + ...
• Sequence Limit: lim n→∞ aₙ