# O

- [Odd and square numbers](/sidef-lang/programming_tasks/o/odd_and_square_numbers.md)
- [Odd squarefree semiprimes](/sidef-lang/programming_tasks/o/odd_squarefree_semiprimes.md)
- [Odd word problem](/sidef-lang/programming_tasks/o/odd_word_problem.md)
- [Old lady swallowed a fly](/sidef-lang/programming_tasks/o/old_lady_swallowed_a_fly.md)
- [Old Russian measure of length](/sidef-lang/programming_tasks/o/old_russian_measure_of_length.md)
- [One-dimensional cellular automata](/sidef-lang/programming_tasks/o/one-dimensional_cellular_automata.md)
- [One-two primes](/sidef-lang/programming_tasks/o/one-two_primes.md)
- [One of n lines in a file](/sidef-lang/programming_tasks/o/one_of_n_lines_in_a_file.md)
- [Operator precedence](/sidef-lang/programming_tasks/o/operator_precedence.md)
- [Optional parameters](/sidef-lang/programming_tasks/o/optional_parameters.md)
- [Orbital elements](/sidef-lang/programming_tasks/o/orbital_elements.md)
- [Order disjoint list items](/sidef-lang/programming_tasks/o/order_disjoint_list_items.md)
- [Order two numerical lists](/sidef-lang/programming_tasks/o/order_two_numerical_lists.md)
- [Ordered partitions](/sidef-lang/programming_tasks/o/ordered_partitions.md)
- [Ordered words](/sidef-lang/programming_tasks/o/ordered_words.md)
- [Own digits power sum](/sidef-lang/programming_tasks/o/own_digits_power_sum.md)