A026371 a(n) = least k such that s(k) = n, where s = A026370.

1, 2, 3, 5, 6, 8, 9, 11, 12, 13, 14, 16, 17, 19, 20, 21, 22, 24, 25, 27, 28, 29, 30, 32, 33, 35, 36, 38, 39, 41, 42, 43, 44, 46, 47, 49, 50, 51, 52, 54, 55, 57, 58, 60, 61, 63, 64, 65, 66, 68, 69, 71, 72, 73, 74, 76, 77, 79, 80, 82, 83, 85, 86

Offset: 1

Author

Clark Kimberling

Keywords

• nonn

Comments

Complement of A026372; also the rank transform (as at A187224) of (A004526 after removal of its first term, leaving 0,1,1,2,2,3,3,4,4,5,5,6,6,...). - Clark Kimberling, Mar 10 2011

Crossrefs

Cf. A187422, A026372, A004526.

Programs

Mathematica

seqA = Table[Floor[n/2], {n, 1, 180}]  (* A004526 *)
seqB = Table[n, {n, 1, 80}];           (* A000027 *)
jointRank[{seqA_, seqB_}] := {Flatten@Position[#1, {_, 1}],
Flatten@Position[#1, {_, 2}]} &[Sort@Flatten[{{#1, 1} & /@ seqA,
{#1, 2} & /@ seqB}, 1]];
limseqU = FixedPoint[jointRank[{seqA, #1[[1]]}] &, jointRank[{seqA, seqB}]][[1]]                                   (* A026371 *)
Complement[Range[Length[seqA]], limseqU]  (* A026372 *)
(* by Peter J. C. Moses, Mar 10 2011 *)