Its first editions were in paper format: http://www.amazon.com/Encyclopedia-Integer-Sequences-N-Sloane/dp/0125586302 http://www.amazon.com/Encyclopedia-Integer

Its first editions were in paper format: http://www.amazon.com/Encyclopedia-Integer-Sequences-N-Sloane/dp/0125586302 http://www.amazon.com/Encyclopedia-Integer-Sequences-N-Sloan... and the original, from 1973, http://www.amazon.com/Handbook-Integer-Sequences-N-Sloane/dp/012648550X/ref=ntt_at_ep_dpi_2 http://www.amazon.com/Handbook-Integer-Sequences-N-Sloane/dp...