0,2

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

N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 (includes this sequence).

J. Riordan, An Introduction to Combinatorial Analysis, Wiley, 1958, p. 83.

Sequence in context: A064327 A134277 A085340 this_sequence A006129 A022515 A059730

Adjacent sequences: A001905 A001906 A001907 this_sequence A001909 A001910 A001911

nonn

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