3,1

D. H. and Emma Lehmer, Cyclotomy for nonsquare-free moduli, pp. 276-300 of Analytic Number Theory (Philadelphia 1980), Lect. Notes Math. 899 (1981).

N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).

Sequence in context: A017744 A053108 A016888 this_sequence A060349 A036354 A016948

Adjacent sequences: A006309 A006310 A006311 this_sequence A006313 A006314 A006315

nonn

N. J. A. Sloane (njas(AT)research.att.com).