Title: The Encyclopedia of Integer Sequences: Unlocking the Mysterious Patterns of Numbers Have you ever encountered a sequence of numbers and wondered, "What number comes next?" It's a common question, but the answer is not always so easy to find. That's where the Encyclopedia of Integer Sequences comes in. This mathematical database, often referred to as OEIS (On-Line Encyclopedia of Integer Sequences), is a vast collection of sequences of integers, ranging from the simple (1, 2, 3, 4, 5) to the complex (the coefficients of the elliptic modular function of level 17). Created in 1964 by Neil Sloane, the OEIS has since grown to include over 362,000 entries. So why should you care about integer sequences? For starters, they can be found in numerous branches of mathematics and science, from number theory to computer science to physics. They also appear in everyday settings, such as in music and art, where patterns and sequences play a crucial role. With the OEIS, you can input a sequence of numbers and immediately access information on its properties, related sequences, and even references to scientific publications. But the real fun comes with exploring the mysterious patterns found within these sequences. Take, for example, the famous Fibonacci sequence: 0, 1, 1, 2, 3, 5, 8, 13, 21, 34, 55, 89, 144, ... This sequence, where each number is the sum of the previous two, appears in nature in the form of spiral patterns and even the growth of plants. But did you know that there is an entire family of related sequences, such as the Lucas sequence and the Pell sequence, that also display intriguing patterns? With the OEIS, the possibilities for discovering and understanding integer sequences are endless. So the next time you encounter a sequence of numbers, don't just scratch your head and wonder what number comes next - turn to the Encyclopedia of Integer Sequences and unlock the mysteries of the mathematical world. The Encyclopedia of Integer Sequences, likened to the FBI's fingerprint database, has reached 362,765 entries in its 50th year. It serves as a mathematical resource for determining the next number in a sequence.