maths.free › Combinatorics & Graph Theory › The Many Faces of Combinatorics › Arithmetic Combinatorics
Arithmetic Combinatorics
In recent years, a great deal of attention has been focused on topics in arithmetic combinatorics, with a number of deep and exciting discoveries in the offing.
Arithmetic Combinatorics
In recent years, a great deal of attention has been focused on topics in arithmetic combinatorics, with a number of deep and exciting discoveries in the offing. In some sense, this area is closely aligned with Ramsey theory and number theory, but recent work shows connections with real and complex analysis, as well. Furthermore, the roots of arithmetic combinatorics go back many years. In this section, we present a brief overview of this rich and rapidly changing area.
Recall that an increasing sequence \(a_1\lt a_2\lt a_3\lt \dots\lt a_t)\) of integers is called an arithmetic progression when there exists a positive integer \(d\) for which \(a_{i+1}-a_i=d\), for all \(i=1,2,\dots,t-1\). The integer \(t\) is called the length of the arithmetic progression.
Material will be added here.
Núna ūú Engin reiknivél leysir þetta, en hlutar þess eru reiknanlegir. Prófaðu einn hér fyrir neðan, eða sláðu inn þinn eigin.
Ókeypis reikningur bætir við athugasemdum við hverja kennslustund, skrá yfir það sem þú hefur lokið, leyst vandamál á einum stað og kennari sem þú getur spurt um þessa síðu.Stærðfræðin sjálf er opin öllum, skráður inn eða ekki.
Skráðu þig inn InnskráningTákn notuð hér
Pikkaðu á hvaða tákn sem er fyrir fulla skilgreiningu, mynd og hvað hvert bréf í því merkir.
Spurningar sem fólk spyr
Permutation or combination?
Ask whether order matters. A lock code is a permutation (order matters); a hand of cards is a combination (it does not).
What is a graph in this sense?
Dots (vertices) joined by lines (edges), not a plot. Road maps, social networks and molecules are graphs; questions like "is there a route" and "how few colours" are graph theory.
Hlutar þessarar síðu eru aðlagað frá Keller & Trotter, Applied Combinatorics (CC BY-SA 4.0). Þjappað og endurútskýrt hér; villur eru okkar.
Meira í Combinatorics & Graph Theory
The counting principlesPigeonhole principle and inclusion, exclusionBinomial coefficients and Pascal's triangleRecurrences and generating functionsGraphs: vertices, edges, degreesPaths, cycles, trees, Euler and HamiltonColouring and planar graphs