OFFSET
1,2
MATHEMATICA
f[seq_] := Riffle[Take[Reverse[seq], #], Take[seq, #]] &[Floor[Length[seq]/2]];
rows = 200; row[1] = Table[n, {n, rows}];
Table[row[n + 1] = Flatten[{f[Take[row[n], 2 n - 1]], Drop[row[n], 2 n - 1]}], {n, Floor[(rows - 1)/3 + 1]}];
TableForm[Table[Take[row[n], 20], {n, 1, 20}]] (* A282347 *)
Table[row[n][[n]], {n, 2 + Floor[(rows - 1)/3]}] (* A282348 *)
CROSSREFS
KEYWORD
nonn,easy,changed
AUTHOR
Clark Kimberling, Feb 13 2017.
STATUS
approved