This file is from Wikimedia Commons and may be used by other projects.
The description on its file description page there is shown below.
Summary
DescriptionEven-index Bernoulli numbers.png
English: Absolute value of even-index Bernoulli numbers (except B0) and relation to the Riemann zeta function
The odd-index Bernoulli numbers are zero, except for B1. The red curve is the function that approximates the absolute value of the even-index Bernoulli numbers, and the yellow curve is the ratio of the two, which is equal to the Riemann zeta function.
to share – to copy, distribute and transmit the work
to remix – to adapt the work
Under the following conditions:
attribution – You must give appropriate credit, provide a link to the license, and indicate if changes were made. You may do so in any reasonable manner, but not in any way that suggests the licensor endorses you or your use.
share alike – If you remix, transform, or build upon the material, you must distribute your contributions under the same or compatible license as the original.