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A098728 Consider the sequence {b(n), n >= 1} of digits of the natural (or counting) numbers: 1 2 3 4 5 6 7 8 9 1 0 1 1 1 2 1 3 1 4 1 5 1 6 1 7 1 8 1 9 2 0... (A007376); a(n) = n - b(n). 2

%I #7 Aug 07 2019 18:42:35

%S 0,0,0,0,0,0,0,0,0,9,11,11,12,13,13,15,14,17,15,19,16,21,17,23,18,25,

%T 19,27,20,28,31,30,32,32,33,34,34,36,35,38,36,40,37,42,38,44,39,46,40,

%U 47,51,49,52,51,53,53,54,55,55,57,56,59,57,61,58,63,59,65,60,66,71,68,72

%N Consider the sequence {b(n), n >= 1} of digits of the natural (or counting) numbers: 1 2 3 4 5 6 7 8 9 1 0 1 1 1 2 1 3 1 4 1 5 1 6 1 7 1 8 1 9 2 0... (A007376); a(n) = n - b(n).

%C Subtract each digit of the counting numbers from its rank.

%H Harvey P. Dale, <a href="/A098728/b098728.txt">Table of n, a(n) for n = 0..1000</a>

%e The sequence of digits of the counting numbers is

%e 1 2 3 4 5 6 7 8 9 1 0 1 1 1 2 1 3 1 4 1 5 1 6 1 7 1 8 1 9 2 0...

%e The 15th term, for instance, is a 2. Thus 15-2=13 is the 15th term of this sequence.

%e Next one is a 1, thus 16 (the rank) - 1 (the 16th digit of the decimal expansion of the counting numbers) = 15, which is the 16th term of this sequence.

%e Next one is 17-3=14

%t With[{c=Flatten[IntegerDigits/@Range[70]]},#[[1]]-#[[2]]&/@Partition[ Riffle[ Range[Length[c]],c],2]] (* _Harvey P. Dale_, Aug 07 2019 *)

%K base,easy,nonn

%O 0,10

%A _Alexandre Wajnberg_, Sep 30 2004

%E More terms from Stacy Hawthorne (shawtho1(AT)ashland.edu), Jan 12 2006

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Last modified October 3 11:12 EDT 2023. Contains 365861 sequences. (Running on oeis4.)