A290019 Sort the positive integers according to 3 keys, which are, in order of priority, number of digits, omega (A001221), and the number itself.

1, 2, 3, 4, 5, 7, 8, 9, 6, 11, 13, 16, 17, 19, 23, 25, 27, 29, 31, 32, 37, 41, 43, 47, 49, 53, 59, 61, 64, 67, 71, 73, 79, 81, 83, 89, 97, 10, 12, 14, 15, 18, 20, 21, 22, 24, 26, 28, 33, 34, 35, 36, 38, 39, 40, 44, 45, 46, 48, 50, 51, 52, 54, 55, 56, 57, 58, 62, 63

Offset

1,2

Links

Alois P. Heinz, Table of n, a(n) for n = 1..9999

Index entries for sequences that are permutations of the natural numbers

Mathematica

Table[SortBy[Range[10^(n - 1), 10^n - 1], PrimeNu], {n, 2}] // Flatten (* Michael De Vlieger, Jul 20 2017 *)

Prog

(PARI) upto(t10nm1) = {my(v, res = []); for(i=1, t10nm1, res = concat(res, vecsort(vector(9*10^(i-1), j, k=j+10^(i-1)-1; [omega(k), k])))); vector(#res, i, res[i][2])}

Crossrefs

Cf. A001221, A055642, A290020.

Sequence in context: A228683 A133017 A371266 * A161924 A034153 A004725

Adjacent sequences: A290016 A290017 A290018 * A290020 A290021 A290022

Keyword

nonn,base

Author

David A. Corneth, Jul 19 2017

Extensions

Definition clarified by Giovanni Resta, Jul 27 2017

Status

approved