r-base-html binary package in Ubuntu Focal amd64

 R is a system for statistical computation and graphics. It consists
 of a language plus a run-time environment with graphics, a debugger,
 access to certain system functions, and the ability to run programs
 stored in script files.
 .
 The design of R has been heavily influenced by two existing languages:
 Becker, Chambers & Wilks' S and Sussman's Scheme. Whereas the
 resulting language is very similar in appearance to S, the underlying
 implementation and semantics are derived from Scheme.
 .
 The core of R is an interpreted computer language which allows
 branching and looping as well as modular programming using functions.
 Most of the user-visible functions in R are written in R. It is
 possible for the user to interface to procedures written in the
 C, C++, or FORTRAN languages for efficiency, and many of R's core
 functions do so. The R distribution contains functionality for a
 large number of statistical procedures and underlying applied math
 computations. There is also a large set of functions which provide
 a flexible graphical environment for creating various kinds of data
 presentations.
 .
 Additionally, several thousand extension "packages" are available from
 CRAN, the Comprehensive R Archive Network, many also as Debian packages,
 named 'r-cran-<name>'.
 .
 This package provides html documentation suitable for browsing with a
 web-browser for the libraries included in the r-base package. It is not
 a required package as the same documentation is already included for
 on-line browsing.

Source package