MathDB
2000 Algebra #4: Multiplications using Powers of x

Source:

October 5, 2014

Problem Statement

What is the fewest number of multiplications required to reach x2000x^{2000} from xx, using only previously generated powers of xx? For example xx2x4x8x16x32x64x128x256x512x1024x1536x1792x1920x1984x2000x\rightarrow x^{2}\rightarrow x^{4}\rightarrow x^{8}\rightarrow x^{16}\rightarrow x^{32}\rightarrow x^{64}\rightarrow x^{128}\rightarrow x^{256}\rightarrow x^{512}\rightarrow x^{1024}\rightarrow x^{1536}\rightarrow x^{1792}\rightarrow x^{1920}\rightarrow x^{1984}\rightarrow x^{2000} uses 1515 multiplications.