A179801 Count of times n appears in number created by stringing together previous n-1 integers

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

Offset

1,1

Comments

2 first appears for n=121; 3 first appears for n=1011; 4 first appears for n=1121; 5 first appears for n=10111. - Harvey P. Dale, Jul 22 2013

Links

Table of n, a(n) for n=1..101.

Example

a(6)=0 because stringing together the first 5 integers gives the number "12345" and 6 does not appear in 12345.
a(12)=1 because stringing together the first 11 integers gives "1234567891011" and 12 appears once in 1234567891011 (right at the beginning).

Mathematica

Table[idn=IntegerDigits[n]; fid=Flatten[IntegerDigits/@Range[n-1]]; Count[ Partition[ fid, Length[idn], 1], idn], {n, 0, 110}] (* Harvey P. Dale, Jul 22 2013 *)
Table[SequenceCount[Flatten[IntegerDigits/@Range[n-1]], IntegerDigits[n]], {n, 120}] (* Harvey P. Dale, Apr 16 2023 *)

Prog

(PHP) for($x = 1; $x <= 1000; $x++) {
echo "$x: " . substr_count($running, $x) ."<br />" ;
$running = $running . $x ;
}

Crossrefs

Sequence in context: A355454 A107846 A354983 * A374093 A353474 A065202

Adjacent sequences: A179798 A179799 A179800 * A179802 A179803 A179804

Keyword

nonn,base

Author

Dominick Cancilla, Jul 27 2010

Status

approved