1,1
N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
I. Vardi, Computational Recreations in Mathematica. Addison-Wesley, Redwood City, CA, 1991, p. 92.
Eric Weisstein's World of Mathematics, Link to a section of The World of Mathematics.
Sequence in context: A158450 A063406 A013151 * A185320 A196458 A085522
Adjacent sequences: A006715 A006716 A006717 * A006719 A006720 A006721
nonn
N. J. A. Sloane (njas(AT)research.att.com).