1,1

R. K. Guy, Unsolved Problems in Number Theory, E11 and E12.

Eric Weisstein's World of Mathematics, Link to a section of The World of Mathematics.

Cf. A045652.

Sequence in context: A060996 A134378 A101226 this_sequence A149887 A149888 A149889

Adjacent sequences: A030123 A030124 A030125 this_sequence A030127 A030128 A030129

nonn,bref,hard

Eric Weisstein (eric(AT)weisstein.com)