1,2
M. L. Perez et al., eds., Smarandache Notions Journal
Eric Weisstein's World of Mathematics, Link to a section of The World of Mathematics.
Cf. A019514.
Sequence in context: A061028 A012862 A045760 * A193836 A193877 A193186
Adjacent sequences: A046030 A046031 A046032 * A046034 A046035 A046036
nonn
Eric Weisstein (eric(AT)weisstein.com)