Problem 43019. Iterative sum of digits of 2^n number

Created by elias GR

Solve Later

{"relationships":[{"relationshipType":"http://schemas.mathworks.com/matlab/code/2013/relationships/document","targetMode":"","relationshipId":"rId1","target":"/matlab/document.xml"},{"relationshipType":"http://schemas.mathworks.com/matlab/code/2013/relationships/output","targetMode":"","relationshipId":"rId2","target":"/matlab/output.xml"}],"parts":[{"partUri":"/matlab/document.xml","relationship":[],"contentType":"application/vnd.mathworks.matlab.code.document+xml","content":"<?xml version=\"1.0\" encoding=\"UTF-8\"?>\n<w:document xmlns:w=\"http://schemas.openxmlformats.org/wordprocessingml/2006/main\"><w:body><w:p><w:pPr><w:pStyle w:val=\"text\"/></w:pPr><w:r><w:t>Given n, calculate the number 2^n (where n&gt;=0) and</w:t></w:r><w:r><w:t> </w:t></w:r><w:r><w:rPr><w:b/></w:rPr><w:t>iterate</w:t></w:r><w:r><w:t> until the sum of the digits is a single-digit number.</w:t></w:r></w:p><w:p><w:pPr><w:pStyle w:val=\"text\"/></w:pPr><w:r><w:t>Example:</w:t></w:r></w:p><w:p><w:pPr><w:pStyle w:val=\"code\"/></w:pPr><w:r><w:t><![CDATA[ Input  n = 7\n Output sum = 2]]></w:t></w:r></w:p><w:p><w:pPr><w:pStyle w:val=\"text\"/></w:pPr><w:r><w:t>because 2^7 = 128, and 1+2+8=11 and 1+1=2.</w:t></w:r></w:p></w:body></w:document>"},{"partUri":"/matlab/output.xml","contentType":"text/xml","content":"<?xml version=\"1.0\" encoding=\"UTF-8\" standalone=\"no\" ?><embeddedOutputs><metaData><evaluationState>manual</evaluationState><layoutState>code</layoutState><outputStatus>ready</outputStatus></metaData><outputArray type=\"array\"/><regionArray type=\"array\"/></embeddedOutputs>"}]}

Solve

Solution Stats

59 Solutions
24 Solvers

Last Solution submitted on Jul 12, 2021

Last 200 Solutions

Problem Comments

5 Comments

5 Comments

Show 2 older comments

goc3 on 5 Oct 2016

I clarified the problem statement and fixed one test case to make the problem solvable as originally intended.

James on 6 Oct 2016

Anyone else running into an issue with 2^111? I'm getting 2^111 = 2596148429267413814265248164610048, which sums to 143, which sums to 8. The test suite says 9.

Binbin Qi on 11 Nov 2016

The last test is not correct. Could you check it ?

Jean-Marie Sainthillier on 30 May 2017

Yes, this is a sequence (1 2 4 8 7 5 1 2 4 8 7 5 ...)

ChrisR on 12 Jul 2021 at 13:25

The test with n = 111 is still incorrect.

Problem Recent Solvers24

Problem Tags

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Problem 43019. Iterative sum of digits of 2^n number

Solution Stats

Last 200 Solutions

Problem Comments

Problem Recent Solvers24

Suggested Problems

More from this Author2

Problem Tags

Community Treasure Hunt

Problem 43019. Iterative sum of digits of 2^n number

Solution Stats

Last 200 Solutions

Problem Comments

Problem Recent Solvers24

Suggested Problems

More from this Author2

Problem Tags

Community Treasure Hunt

Players