A356380 Main diagonal of the LIRO variant of the array A035486; this is one of eight such sequences discussed in A007063.

1, 3, 5, 6, 4, 11, 13, 2, 7, 14, 24, 9, 10, 31, 35, 33, 27, 23, 38, 42, 46, 54, 37, 44, 52, 34, 17, 21, 26, 77, 79, 45, 28, 40, 12, 70, 36, 72, 69, 66, 90, 75, 47, 67, 95, 76, 126, 43, 108, 87, 74, 133, 88, 60, 116, 99, 102, 86, 151, 111, 156, 169, 173, 171

Offset: 1

Author

Clark Kimberling, Oct 24 2022

Keywords

• nonn

Comments

Conjecture: every positive integer occurs exactly once.

Crossrefs

Cf. A007063, A035486.

Programs

Mathematica

lori = Join[{{1}}, NestList[Join[#[[Riffle[Range[1, (Length[#] - 1)/2],
      Range[(Length[#] + 3)/2, Length[#]]]]],
      Range[#, # + 2] &[(3 Length[#] + 1)/2]] &, {2, 3, 4}, 200]];
s = Map[{#, Take[Flatten[Map[Take[#, {(Length[#] + 1)/2}] &, #]], 150] &[
      ToExpression[#]]} &, {"lori"}];
Last[First[s]]   (* A356379 *)
(* Peter J. C. Moses, Jul 26 2022 *)
(* The next program generates the LIRO array. *)
len = 8; liro = Join[{{1}}, NestList[Join[#[[Riffle[Range[(Length[#] - 1)/2, 1, -1],
     Range[Length[#], (Length[#] + 3)/2, -1]]]],
     Range[#, # + 2] &[(3 Length[#] + 1)/2]] &, {2, 3, 4}, len]];
Grid[Map[Flatten, Transpose[{#, Range[3 Range[Length[#]] - 1,
       4 (Length[#] - 2) - 1 + Range[Length[#]]]}]] &[liro]]
(* Peter J. C. Moses, Aug 02 2022 *)