A337843 a(n) is n + the number of digits in the decimal expansion of n.

1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69

Offset

0,2

Comments

a(n) is an increasing injective sequence that is not surjective.

a(n) is also the sequence of numbers m that can be written as (m + number of digits of m) for some m >= 0, complement of numbers from A081552(n) for n > 1.

Sequence is not the same as A101947, first different term is a(77) = 79.

Links

Table of n, a(n) for n=0..67.

Formula

a(n) = n + A055642(n).

Example

a(10) = 10 + 2 = 12.

Mathematica

a[0] = 1; a[n_] := n + IntegerLength[n]; Array[a, 100, 0] (* Amiram Eldar, Sep 25 2020 *)

Prog

(Magma) [1] cat [n + #Intseq(n): n in [1..100]]
(PARI) a(n) = if (n==0, 1, n + #digits(n)); \\ Michel Marcus, Sep 26 2020

Crossrefs

Cf. A055642, A062028, A081552, A230099.

Cf. A110803 (n * the number of digits in the decimal expansion of n).

Sequence in context: A020753 A353888 A331162 * A101947 A183223 A167520

Adjacent sequences: A337840 A337841 A337842 * A337844 A337845 A337846

Keyword

nonn,base

Author

Jaroslav Krizek, Sep 25 2020

Status

approved