A120619 a(n) = b(n)th integer among those positive integers not yet occurring in {a(k)}, where {b(k)} is the concatenation of the divisors of the positive integers.

1, 2, 4, 3, 7, 5, 8, 11, 6, 14, 9, 12, 15, 19, 10, 22, 13, 17, 21, 27, 16, 23, 31, 18, 24, 29, 36, 20, 39, 25, 28, 32, 34, 38, 46, 26, 49, 30, 35, 44, 54, 33, 41, 45, 59, 37, 42, 48, 55, 65, 40, 68, 43, 50, 52, 58, 63, 75, 47, 78, 51, 56, 61, 64, 72, 85, 53, 62, 71, 90, 57, 66

Offset

1,2

Comments

b(n) = A027750(n). {a(n)} is a permutation of the positive integers.

Links

Rémy Sigrist, Table of n, a(n) for n = 1..10000

Index entries for sequences that are permutations of the natural numbers

Example

The first 6 terms of {a(k)} are 1,2,4,3,7,5. So the positive integers not occurring among these terms are 6,8,9,10,... The 7th term of A027750 is 2. So a(7) = 8.

Prog

(PARI) { val = List([1..90]); n = 0; for (m=1, oo, fordiv (m, d, v = val[d]; listpop(val, d); print1 (v", "); if (n++==72, break (2)))) } \\ Rémy Sigrist, Apr 20 2022

Crossrefs

Cf. A027750, A120620.

Sequence in context: A191666 A215673 A352716 * A346298 A084385 A073885

Adjacent sequences: A120616 A120617 A120618 * A120620 A120621 A120622

Keyword

nonn

Author

Leroy Quet, Jun 18 2006

Extensions

Extended by Ray Chandler, Jun 19 2006

Edited by Charles R Greathouse IV, Apr 27 2010

Status

approved