A328752 Lexicographically earliest sequence of distinct positive numbers such that for any n > 0, the first nonzero digit of a(n+1)/a(n) is "1".

1, 10, 11, 2, 3, 4, 5, 6, 7, 8, 9, 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

Offset

1,2

Comments

In other words, for any n > 0, we have an integer k such that floor(10^k * a(n+1)/a(n)) = 1.

Links

Table of n, a(n) for n=1..67.

Rémy Sigrist, PARI program for A328752

Formula

a(n) = n for n > 11.

Example

The first terms, alongside a(n+1)/a(n), are:
  n   a(n)  a(n+1)/a(n)
  --  ----  -----------
   1     1  10
   2    10   1.1
   3    11   0.18181818...
   4     2   1.5
   5     3   1.33333333...
   6     4   1.25
   7     5   1.2
   8     6   1.16666666...
   9     7   1.14285714...
  10     8   1.125
  11     9   1.33333333...
  12    12   1.08333333...

Prog

(PARI) See Links section.

Crossrefs

See A328753, A328754, A328755, A328756, A328757, A328758, A328759 and A328760 for the variants where a(n+1)/a(n) starts with "2", "3", "4", "5", "6", "7", "8" and "9", respectively.

Sequence in context: A336035 A334676 A176998 * A173821 A101807 A248025

Adjacent sequences: A328749 A328750 A328751 * A328753 A328754 A328755

Keyword

nonn,base

Author

Rémy Sigrist, Oct 27 2019

Status

approved