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Revision History for A102678

(Underlined text is an addition; strikethrough text is a deletion.)

Showing entries 1-10 | older changes
A102678 Number of digits >= 6 in the decimal representations of all integers from 0 to n.
(history; published version)
#20 by Michael De Vlieger at Wed Nov 16 17:26:39 EST 2022
STATUS

proposed

approved

#19 by Michel Marcus at Wed Nov 16 16:38:00 EST 2022
STATUS

editing

proposed

#18 by Michel Marcus at Wed Nov 16 16:37:57 EST 2022
FORMULA

Contribution fromFrom Hieronymus Fischer, Jun 10 2012 (: (Start):)

STATUS

approved

editing

#17 by Jon E. Schoenfield at Thu Aug 17 02:48:24 EDT 2017
STATUS

editing

approved

#16 by Jon E. Schoenfield at Thu Aug 17 02:48:22 EDT 2017
FORMULA

a(n) = (1/2)*sumSum_{j=1..m+1} (floor(n/10^j + 2/5)*(2n + 2 - (1/5 + floor(n/10^j + 2/5))*10^j) - floor(n/10^j)*(2n + 2 - (1+floor(n/10^j)) * 10^j)), where m= = floor(log_10(n)).

a(n) = (n+1)*A102677(n) + (1/2)*sumSum_{j=1..m+1} ((-1/5*floor(n/10^j + 2/5) + floor(n/10^j))*10^j - (floor(n/10^j + 2/5)^2 - floor(n/10^j)^2)*10^j), where m= = floor(log_10(n)).

G.f.: g(x) = (1/(1-x)^2)*sumSum_{j>=0} (x^(6*10^j) - x^(10*10^j))/(1- - x^10^(j+1)). (End)

MAPLE

p:=proc(n) local b, ct, j: b:=convert(n, base, 10): ct:=0: for j from 1 to nops(b) do if b[j]>=6 then ct:=ct+1 else ct:=ct fi od: ct: end: seq(add(p(i), i=0..n), n=0..86); (_); # _Emeric Deutsch_)_, Feb 23 2005

STATUS

approved

editing

#15 by N. J. A. Sloane at Mon Nov 04 21:48:40 EST 2013
STATUS

proposed

approved

#14 by Jon E. Schoenfield at Mon Nov 04 21:07:03 EST 2013
STATUS

editing

proposed

#13 by Jon E. Schoenfield at Mon Nov 04 21:07:01 EST 2013
COMMENTS

The total number of digits >= 6 occurring in all the numbers 0, 1, 2, ... n (in decimal representation). - ). - _Hieronymus Fischer, _, Jun 10 2012

MAPLE

p:=proc(n) local b, ct, j: b:=convert(n, base, 10): ct:=0: for j from 1 to nops(b) do if b[j]>=6 then ct:=ct+1 else ct:=ct fi od: ct: end: seq(add(p(i), i=0..n), n=0..86); (); (_Emeric Deutsch)_)

STATUS

approved

editing

#12 by N. J. A. Sloane at Sun Nov 03 17:01:01 EST 2013
FORMULA

Contribution from _Hieronymus Fischer, _, Jun 10 2012 (Start):

Discussion
Sun Nov 03 17:01
OEIS Server: https://oeis.org/edit/global/2040
#11 by N. J. A. Sloane at Wed May 01 21:12:45 EDT 2013
EXTENSIONS

An incorrect g.f. was deleted by _N. J. A. Sloane, _, Sep 16 2009

Discussion
Wed May 01 21:12
OEIS Server: https://oeis.org/edit/global/1902

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Last modified August 18 11:16 EDT 2024. Contains 375265 sequences. (Running on oeis4.)