1,2

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

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

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

Sequence in context: A073915 A076381 A063455 this_sequence A121253 A014118 A007704

Adjacent sequences: A001141 A001142 A001143 this_sequence A001145 A001146 A001147

nonn

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