A328760 Lexicographically earliest sequence of distinct positive numbers such that for any n > 0, the first nonzero digit of a(n+1)/a(n) is "9".

1, 9, 81, 8, 72, 7, 63, 6, 54, 5, 45, 41, 4, 36, 33, 3, 27, 25, 23, 21, 2, 18, 17, 16, 15, 14, 13, 12, 11, 10, 90, 82, 74, 67, 61, 55, 50, 46, 42, 38, 35, 32, 29, 28, 26, 24, 22, 20, 19, 171, 154, 139, 126, 114, 103, 93, 84, 76, 69, 64, 58, 53, 48, 44, 40, 37

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)) = 9.

The scatterplot of n -> a(n)/n shows 22 quivering lines.

Links

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

Example

The first terms, alongside a(n+1)/a(n), are:
  n   a(n)  a(n+1)/a(n)
  --  ----  -----------
   1     1  9
   2     9  9
   3    81  0.098765...
   4     8  9
   5    72  0.097222...
   6     7  9
   7    63  0.095238...
   8     6  9
   9    54  0.092592...
  10     5  9
  11    45  0.911111...
  12    41  0.097560...

Crossrefs

See A328752 for similar sequences.

Sequence in context: A352386 A332702 A117817 * A228591 A219664 A107346

Adjacent sequences: A328757 A328758 A328759 * A328761 A328762 A328763

Keyword

nonn,base

Author

Rémy Sigrist, Oct 27 2019

Status

approved