A237056 Ludic and non-ludic numbers interleaved.

1, 4, 2, 6, 3, 8, 5, 9, 7, 10, 11, 12, 13, 14, 17, 15, 23, 16, 25, 18, 29, 19, 37, 20, 41, 21, 43, 22, 47, 24, 53, 26, 61, 27, 67, 28, 71, 30, 77, 31, 83, 32, 89, 33, 91, 34, 97, 35, 107, 36, 115, 38, 119, 39, 121, 40, 127, 42, 131, 44, 143, 45, 149, 46, 157

Offset: 1

Author

Antti Karttunen and Reinhard Zumkeller, Feb 04 2014

Keywords

• nonn

Comments

a(2*n-1) = A003309(n); a(2*n) = A192607(n);

integer permutation with inverse A237058.

Links

• Reinhard Zumkeller, Table of n, a(n) for n = 1..10000
• Index entries for sequences that are permutations of the natural numbers

Crossrefs

Cf. A073846.

Programs

Haskell

import Data.List (transpose)
a237056 n = a237056_list !! (n-1)
a237056_list = concat $ transpose [a003309_list, a192607_list]

Mathematica

a3309[nmax_] := a3309[nmax] = Module[{t = Range[2, nmax], k, r = {1}}, While[Length[t] > 0, k = First[t]; AppendTo[r, k]; t = Drop[t, {1, -1, k}]]; r];
nmax = 1000;
Riffle[a3309[nmax], Complement[Range[nmax], a3309[nmax]]] (* Jean-François Alcover, Dec 10 2021, after Ray Chandler in A003309 *)