On Generalized Schur Numbers
نویسندگان
چکیده
Let L(t) represent the equation x1 + x2 + · · · + xt−1 = xt. For k > 1, 0 6 i 6 k − 1, and ti > 3, the generalized Schur number S(k; t0, t1, . . . , tk−1) is the least positive integer m such that for every k-colouring of {1, 2, . . . ,m}, there exists an i ∈ {0, 1, . . . , k − 1} such that there exists a solution to L(ti) that is monochromatic in colour i. In this paper, we report twenty-six previously unknown values of S(k; t0, t1, . . . , tk−1) and conjecture that for 4 6 t0 6 t1 6 t2, S(3; t0, t1, t2) = t2t1t0 − t2t1 − t2 − 1.
منابع مشابه
Off-diagonal Generalized Schur Numbers
We determine all values of the 2-colored off-diagonal generalized Schur numbers (also called Issai numbers), an extension of the generalized Schur numbers. These numbers, denoted S(k, l), are the minimal integers such that any red and blue coloring of the integers from 1 to S(k, l) must admit either a solution to ∑k−1 i=1 xi = xk consisting of only red integers, or a solution to ∑l−1 i=1 xi = x...
متن کاملGLn-REPRESENTATIONS BY CHARACTERISTIC-FREE ISOMORPHISMS BETWEEN GENERALIZED SCHUR ALGEBRAS
Isomorphisms are constructed between generalized Schur algebras in different degrees. The construction covers both the classical case (of general linear groups over infinite fields of arbitrary characteristic) and the quantized case (in type A, for any non-zero value of the quantum parameter q). The construction does not depend on the characteristic of the underlying field or the choice of q 6=...
متن کاملGeneralized Drazin inverse of certain block matrices in Banach algebras
Several representations of the generalized Drazin inverse of an anti-triangular block matrix in Banach algebra are given in terms of the generalized Banachiewicz--Schur form.
متن کاملLog-Convexity Properties of Schur Functions and Generalized Hypergeometric Functions of Matrix Argument
We establish a positivity property for the difference of products of certain Schur functions, sλ(x), where λ varies over a fundamental Weyl chamber in R n and x belongs to the positive orthant in R. Further, we generalize that result to the difference of certain products of arbitrary numbers of Schur functions. We also derive a log-convexity property of the generalized hypergeometric functions ...
متن کاملTheoretical results on the global GMRES method for solving generalized Sylvester matrix equations
The global generalized minimum residual (Gl-GMRES) method is examined for solving the generalized Sylvester matrix equation [sumlimits_{i = 1}^q {A_i } XB_i = C.] Some new theoretical results are elaborated for the proposed method by employing the Schur complement. These results can be exploited to establish new convergence properties of the Gl-GMRES method for solving genera...
متن کاملDifference Ramsey Numbers and Issai Numbers
We present a recursive algorithm for finding good lower bounds for the classical Ramsey numbers. Using notions from this algorithm we then give some results for a generalization of the Generalized Schur numbers, which we call Issai numbers.
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
- Experimental Mathematics
دوره 25 شماره
صفحات -
تاریخ انتشار 2016