The first term of a sequence is \(2014\). Each succeeding term is the sum of the cubes of the digits of the previous term. What is the \(2014^{\text{th}}\) term of the sequence?

This note is part of the set Pre-RMO 2014

The first term of a sequence is \(2014\). Each succeeding term is the sum of the cubes of the digits of the previous term. What is the \(2014^{\text{th}}\) term of the sequence?

This note is part of the set Pre-RMO 2014

No vote yet

1 vote

×

Problem Loading...

Note Loading...

Set Loading...

## Comments

Sort by:

TopNewestLet's define this sequence as \(a_1, a_2, a_3, ..., a_{2014}, ...\) where \(a_1 = 2014\). The sum of the cubes of the digits of 2014 is 73. \(a_2 = 73\). The sum of the cubes of the digits of 73 is 370. \(a_3 = 370\). The sum of the cubes of the digits of 370 is 370 again. From this, we yield \(a_k = a_{k+1}\) for \(k \geq 3\). Therefore, \(a_{2014} = a_3 = 370\). Therefore, the answer is 370. – Sharky Kesa · 2 years, 7 months ago

Log in to reply

– Sachin Vishwakarma · 1 year, 7 months ago

That is an Armstrong number. :-)Log in to reply

– Vedant Saraswat · 2 years, 7 months ago

niceLog in to reply

– Karthik Venkata · 2 years, 4 months ago

An elegant solution.Log in to reply

First term is 2014,as per the given question the second term should be 2^3+1^3+4^3=73.Similarly third term will be 7^3 + 3^3 = 370.Now the rest of the terms as we go further comes out to be 370. So the ans is 370. – Vivek Rao · 2 years, 7 months ago

Log in to reply

the answer is 370 because all the terms after the third term are 370 – Abhishek Alva · 10 months, 1 week ago

Log in to reply

370 – Gaurav Singh · 1 year, 9 months ago

Log in to reply

\(1^{st}\) term \(=2014\)

\(2^{nd}\) term \(=73\)

\(3^{rd}\) term \(=370\)

\(4^{th}\) term \(=370\)

. . .

Same goes on and \(2014^{th}\) term \(=\boxed{370}\) – Akshat Sharda · 1 year, 9 months ago

Log in to reply

370 :). – Luana De Moraes · 2 years, 5 months ago

Log in to reply

370 – Karthi Kn · 2 years, 6 months ago

Log in to reply

370 – Archit Agarwal · 2 years, 7 months ago

Log in to reply

370 – Vedant Saraswat · 2 years, 7 months ago

Log in to reply

370 – Zahra Y · 2 years, 7 months ago

Log in to reply

370 – Shudipta _Cuet12 · 2 years, 7 months ago

Log in to reply

370 – Subhajit Ghosh · 2 years, 7 months ago

Log in to reply

Here 2014=2^3+1^3+4^3=73 Second term =7^3+3^3=370 Third term=3^3+7^3=370 Therefore k>=3. Then a=370 – Harish Krishnan · 2 years, 7 months ago

Log in to reply

370 – Harish Krishnan · 2 years, 7 months ago

Log in to reply

Here I term is 2014. Second term is (2^3+0^3+1^3+4^3)=73. Third term is (7^4+3^3)=370. Now it is clear that ii and iii digits have only two natural no. And now if we sum the cube of digits then it will remain 370. Hence after iii term all the terms of this series will be 370. Hence answer is 370. – Rahul Verma · 2 years, 7 months ago

Log in to reply

370 – Pulkit Kapoor · 2 years, 7 months ago

Log in to reply