MathDB

An arithmetic sequence is a sequence of

(a_1, a_2, \dots, a_n)

such that the difference between any two consecutive terms is the same. That is,

a_ {i + 1} -a_i = d

for all

i \in \{1,2, \dots, n-1 \}

, where

d

is the difference of the progression.
A sequence

(a_1, a_2, \dots, a_n)

is tlaxcalteca if for all

i \in \{1,2, \dots, n-1 \}

, there exists

m_i

positive integer such that

a_i = \frac {1} {m_i}

. A taxcalteca arithmetic progression

(a_1, a_2, \dots, a_n )

is said to be maximal if

(a_1-d, a_1, a_2, \dots, a_n)

and

(a_1, a_2, \dots, a_n, a_n + d)

are not Tlaxcalan arithmetic progressions.
Is there a maximal tlaxcalteca arithmetic progression of

11

elements?

Problem Statement