2,2
R. K. Guy, Catwalks, Sandsteps and Pascal Pyramids, J. Integer Seqs., Vol. 3 (2000), #00.1.6
Sequence in context: A090230 A133652 A004058 * A123902 A085374 A016283
Adjacent sequences: A052175 A052176 A052177 * A052179 A052180 A052181
nonn
N. J. A. Sloane (njas(AT)research.att.com), Jan 26 2000