sudo snap install bitcoin-core, which worked but I've read that it cannot be trusted, so I uninstalled it
the developer, bitcoincore.org, doesn't seem to maintain a binary for Ubuntu (or any other distribution) but provides a tar file. they supply no instructions for how to install the software and I can't seem to find anything simple. all I want is to install a running node (so there should be a startup script with SysV/InetD/startup, or whatever system Ubuntu is inclined to use now for automatically running services at boot-time)
can anyone point me to a working guide?