An electronic copy of the tenth printing of this famous reference.
(Personally, I think the “frames” interface is the most useful.)
You can download an copy of Abramowitz and Stegun: Handbook of Mathematical Functions as a tar.gz archive. This is a 43 MiB file (md5sum: e6ca7451af4e4ffad42aa6b8deb552c7). Untar it somewhere and open the index.htm file in your browser.
If you host a copy, let me know at cbm[at]sfu.ca and I will add it to the list.
The individual who originally scanned this work has contacted me but wishes to remain anonymous.
Abramowitz and Stegun: Handbook of Mathematical Functions is a work commissioned by the government of the United States of America and, to the best of my knowledge, is not under copyright.
Colin Macdonald reserves no rights on this page.