MathDB
Find the least n_k

Source:

August 28, 2010
floor functionceiling functionnumber theory unsolvednumber theory

Problem Statement

Given a positive integer kk, find the least integer nkn_k for which there exist five sets S1,S2,S3,S4,S5S_1, S_2, S_3, S_4, S_5 with the following properties: |S_j|=k \text{ for } j=1, \cdots , 5 ,   |\bigcup_{j=1}^{5} S_j | = n_k ; |S_i \cap S_{i+1}| = 0 = |S_5 \cap S_1|,   \text{for } i=1,\cdots ,4