O
O'Halloran numbersObject serializationOdd and square numbersOdd squarefree semiprimesOdd word problemOdd wordsOld lady swallowed a flyOld Russian measure of lengthOne-dimensional cellular automataOne-time padOne-two primesOne of n lines in a fileOpenGLOpenWebNet passwordOperator precedenceOptional parametersOrbital elementsOrder by pair comparisonsOrder disjoint list itemsOrder two numerical listsOrdered partitionsOrdered wordsOrmiston pairsOrmiston triplesOverloaded operatorsOwn digits power sum