A237056 - OEIS

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

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OFFSET

1,2

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

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 *)

PROG

(Haskell)

import Data.List (transpose)

a237056 n = a237056_list !! (n-1)

a237056_list = concat $ transpose [a003309_list, a192607_list]

CROSSREFS

Cf. A073846.

Sequence in context: A163238 A097362 A129131 * A285296 A257885 A257908

Adjacent sequences: A237053 A237054 A237055 * A237057 A237058 A237059

KEYWORD

nonn

AUTHOR

Antti Karttunen and Reinhard Zumkeller, Feb 04 2014

STATUS

approved