Services & Resources / Wolfram Forums
MathGroup Archive
*Archive Index
*Ask about this page
*Print this page
*Give us feedback
*Sign up for the Wolfram Insider

MathGroup Archive 2005

[Date Index] [Thread Index] [Author Index]

Search the Archive

Re: challenge problem

  • To: mathgroup at
  • Subject: [mg61291] Re: [mg61219] challenge problem
  • From: Zhengji Li < at>
  • Date: Fri, 14 Oct 2005 05:56:10 -0400 (EDT)
  • References: <> <>
  • Sender: owner-wri-mathgroup at

A further look at the lucky sevens showing that they are in the form:
7, 77, 777, ....

So we can get the result just in a blink:
Sum[7 FromDigits@Table[1, {i}], {i, 11}]

Li Zhengji
If all you have is a hammer, everything is a nail.

  • Prev by Date: Re: challenge problem
  • Next by Date: Re: How to reverse sign on the y's in a list of (x, y)'s?
  • Previous by thread: Re: challenge problem
  • Next by thread: Re: challenge problem