[This is from Eric Weisstein, sent a week ago.] ------ On Thu, 30 Mar 2006, Robert Baillie wrote:

Problem E2533 in the American Mathematical Monthly (1975 or 1976) says there are 8877690 integers that have distinct digits. The problem is to estimate the sum of their reciprocals.

I thought I read someplace that someone had computed the exact sum. Does anyone know how big the numerator and denominator are? And, by the way, what is the approximate sum?

Assuming I have not made a silly computation error, the exact sum is 6745140117...4801548051 (14816583 digits) ----------------------- 7553392231...8000000000 (14816582 digits) given to 100 digits by 8.929948174755443424171179403981525048667286767255408480936913993018768120557239657437064181411273952 which will appear shortly on http://mathworld.wolfram.com/Digit.html http://www.research.att.com/~njas/sequences/?q=A117914 Cheers, -Eric