The Louvre Museum as seen through the Louvre Pyramid glass in Paris, France. From the National Geographic book The 10 Best of Everything. Smithsonian Institution, Washington, D.C. The Smithsonian is the worldâs largest research and museum complex, with 19 museums and galleries, the National Zoological Park, and various research stations.
1 An arithmetic sequence is a sequence with the difference between two consecutive terms constant. 2  The difference is called the common difference. 3  A geometric sequence is a sequence with the ratio between two consecutive terms constant. 4  This ratio is called the common ratio.
An arithmetic sequence (or arithmetic progression) is a sequence (finite or infinite list) of real numbers for which each term is the previous term plus a constant (called the common difference).n arithmetic sequence (or arithmetic progression) is a sequence (finite or infinite list) of real numbers for which each term is the previous term plus a constant (called the common difference).