1,4

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

G. B. Huff, On pairings of the first 2n natural numbers, Acta Arithmetica, 23 (1973), 117-126.

R. Spira, Noncomplete residue systems, Problem 71-4, SIAM Rev., 14 (1972), 173ff.

Sequence in context: A112684 A048489 A124701 this_sequence A058404 A126362 A140418

Adjacent sequences: A002965 A002966 A002967 this_sequence A002969 A002970 A002971

nonn

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