The Copeland-Erdős constant is the concatenation of "0." with the base 10 representations of the prime numbers in order. Its value is approximately

0.235711131719232931374143...

The larger Smarandache-Wellin numbers approximate the value of this constant multiplied by the appropriate power of 10.

Its continued fraction is

$0\; +\; \backslash cfrac\{1\}\{4\; +\; \backslash cfrac\{1\}\{4\; +\; \backslash cfrac\{1\}\{8+\backslash ,\backslash cdots\}\}\}$ ()

In base 10, this is a normal number, a fact proven by Arthur Herbert Copeland and Paul Erdős in 1946 (hence the name of the constant).

Copeland-Erdőseva konstanta