A330384 Single-digit numbers in order of appearance in decimal expansions of composite numbers, followed by two-digit numbers in order of appearance, then three-digit numbers and so forth.

4, 6, 8, 9, 1, 0, 2, 5, 7, 3, 10, 12, 14, 15, 16, 18, 20, 21, 22, 24, 25, 26, 27, 28, 30, 32, 33, 34, 35, 36, 38, 39, 40, 42, 44, 45, 46, 48, 49, 50, 51, 52, 54, 55, 56, 57, 58, 60, 62, 63, 64, 65, 66, 68, 69, 70, 72, 74, 75, 76, 77, 78, 80, 81, 82, 84, 85, 86

Offset

1,1

Links

Rémy Sigrist, Table of n, a(n) for n = 1..11000

Rémy Sigrist, Colored scatterplot of the first 110000 terms (red pixels indicate terms that are prime)

Rémy Sigrist, PARI program for A330384

Example

From Rémy Sigrist, Dec 24 2019: (Begin)
The first terms, alongside the corresponding composite numbers, are:
  n   a(n)  Composite
  --  ----  ---------
   1     4          4
   2     6          6
   3     8          8
   4     9          9
   5     1         10
   6     0         10
   7     2         12
   8     5         15
   9     7         27
  10     3         30
  11    10         10
  12    12         12
  13    14         14
  ...
  79    99         99
  80    11        110
  81    17        117
  82    19        119
  83    23        123
(End)

Prog

(PARI) See Links section.

Crossrefs

Cf. A002808, A321043, A321128.

Sequence in context: A110750 A275589 A129808 * A077649 A308375 A329423

Adjacent sequences: A330381 A330382 A330383 * A330385 A330386 A330387

Keyword

nonn,base,look

Author

David Williams, Dec 12 2019

Extensions

More terms from Rémy Sigrist, Dec 24 2019

Status

approved