An information processing program for causing a computer to perform processing including: dividing a sequence indicating a rational formula of a compound, into a character string of a minimum unit of the sequence and a branch symbol indicating a branched portion of the compound; generating a first coded sequence by using a group dictionary indicating a relationship between the sequence and the compression code, the generating including assigning a compression code to the character string of the minimum unit, and assigning the compression code according to a type of the branched portion to the branch symbol; and generating a second coded sequence by using a primary structure dictionary indicating a relationship between a group primary structure of the sequence and the compression code, the generating of the second coded sequence including encoding the compression code in the first coded sequence in units of the group primary structure.