MathDB
m-b_m = 1990

Source: Turkey TST 1990 - P5

September 11, 2013
number theory proposednumber theory

Problem Statement

Let bmb_m be numbers of factors 22 of the number m!m! (that is, 2bmm!2^{b_m}|m! and 2bm+1m!2^{b_m+1}\nmid m!). Find the least mm such that mbm=1990m-b_m = 1990.