A356377 Main diagonal of the ROLI variant of the array A035486; this is one of eight such sequences discussed in A007063.

1, 3, 5, 4, 8, 6, 10, 15, 2, 9, 13, 26, 11, 12, 33, 34, 35, 29, 22, 37, 44, 48, 56, 39, 43, 54, 36, 16, 23, 25, 76, 81, 47, 30, 42, 14, 72, 38, 74, 71, 68, 92, 77, 46, 69, 94, 78, 128, 45, 110, 89, 73, 135, 90, 62, 115, 101, 104, 85, 153, 113, 158, 171, 172

Offset: 1

Author

Clark Kimberling, Oct 21 2022

Keywords

• nonn

Comments

Conjecture: every positive integer occurs exactly once.

Crossrefs

Cf. A007063, A035486.

Programs

Mathematica

len = 8; roli = Join[{{1}}, NestList[Join[#[[Riffle[Range[Length[#], (Length[#] + 3)/2, -1], Range[(Length[#] - 1)/2, 1, -1]]]],
     Range[#, # + 2] &[(3 Length[#] + 1)/2]] &, {2, 3, 4}, 200]];
s = Map[{#, Take[Flatten[Map[Take[#, {(Length[#] + 1)/2}] &, #]], 150] &[
      ToExpression[#]]} &, {"roli"}];
Last[First[s]]   (* A356377 *)
(* Peter J. C. Moses, Jul 26 2022 *)
(* The next program generates the ROLI array. *)
len = 8; roli = Join[{{1}}, NestList[Join[#[[Riffle[Range[Length[#], (Length[#] + 3)/2, -1], Range[(Length[#] - 1)/2, 1, -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[#]]]}]] &[roli]]
(* Peter J. C. Moses, Aug 02 2022 *)