A138885 n-th run has length n-th nonprime number, with digits 0 and 1 only, starting with 1.

1, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1

Offset

1,1

Links

Table of n, a(n) for n=1..79.

Example

.n ..... Run ................... Length
.1 ..... 1 ..................... 1
.2 ..... 0,0,0,0 ............... 4
.3 ..... 1,1,1,1,1,1 ........... 6
.4 ..... 0,0,0,0,0,0,0,0 ....... 8
.5 ..... 1,1,1,1,1,1,1,1,1 ..... 9

Mathematica

Join[{1}, {PadRight[{}, #[[1]], 0], PadRight[{}, #[[2]], 1]}&/@Partition[Select[Range[ 20], CompositeQ], 2]]//Flatten (* Harvey P. Dale, May 26 2023 *)

Crossrefs

Nonprime numbers: A018252. Cf. A057211, A138149, A138150, A138709, A138710, A138711, A138712, A138886.

Sequence in context: A071005 A287801 A089510 * A185115 A240467 A014065

Adjacent sequences: A138882 A138883 A138884 * A138886 A138887 A138888

Keyword

easy,nonn

Author

Omar E. Pol, Apr 06 2008

Status

approved