Sums of Three Powers of Two

Problem

Let

A={2a+2b+2c  :  a,b,cN}A = \left\{2^a + 2^b + 2^c \;:\; a, b, c \in \mathbb{N}\right\}

(the exponents need not be distinct). A subset BAB \subseteq A consists of nn consecutive natural numbers. Find the maximum possible nn.

Answer

Solution

Difficulty7/10
Topicscombinatorics, number theory, Modular Arithmetic, Casework

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