# Hunting e

Of the irrational, transcendental numbers, pi seems to get all the attention. Web sites and books celebrate its quirks and quandaries. Its digits have been computed to 1,241,100,000,000 decimal places.

Lagging far behind in the celebrity sweepstakes is the number known as *e*. Carried to 20 decimal places, *e* is 2.71828 18284 59045 23536. Only 1,250,000,000 of its decimal digits have been computed so far—though there appears to be an unverified computation of 1.7 billion digits. People can't even agree on its proper name. It's been called the logarithmic constant, Napier's number, Euler's constant, and the natural logarithmic base.

One way to define *e* is as the number that the expression (1 + *x*)1/*x* approaches as *x* gets smaller and smaller. Thus, when *x* is 1, the expression equals 2; when *x* is .5, the expressi