1,2

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).

Problem E2118, Amer. Math. Monthly, 76 (1969), 830-831.

Adjacent sequences: A001141 A001142 A001143 this_sequence A001145 A001146 A001147

Sequence in context: A073915 A076381 A063455 this_sequence A121253 A014118 A007704

nonn

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