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#19 by Susanna Cuyler at Tue Dec 10 20:02:56 EST 2019
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#18 by Robert Israel at Tue Dec 10 16:42:43 EST 2019
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#17 by Robert Israel at Tue Dec 10 16:42:35 EST 2019
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| LINKS
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Robert Israel, <a href="/A316864/b316864.txt">Table of n, a(n) for n = 0..10000</a>
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| FORMULA
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From Robert Israel, Dec 10 2019: (Start)
a(10*n+3) = a(n)+1, a(10*n+i)=a(i) for i = 0,1,2,4..9.
G.f. g(z) satisfies g(z) = z^3/(1-z^10) + ((1-z^10)/(1-z))*g(z^10). (End)
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| MAPLE
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f:= proc(n) option remember;
procname(floor(n/10)) + `if`(n mod 10 = 3, 1, 0)
end proc:
for i from 0 to 9 do f(i):= `if`(i=3, 1, 0) od:
map(f, [$0..100]); # Robert Israel, Dec 10 2019
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| STATUS
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approved
editing
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#16 by N. J. A. Sloane at Sat Aug 11 14:07:28 EDT 2018
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#15 by N. J. A. Sloane at Sat Aug 11 14:07:25 EDT 2018
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#14 by Robert G. Wilson v at Sat Aug 04 17:02:39 EDT 2018
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#13 by Robert G. Wilson v at Sat Aug 04 16:56:30 EDT 2018
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| NAME
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Number of digitstimes 3 appears in decimal representationexpansion of n.
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| EXAMPLE
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a(0) = 0 since the decimal representation of 0 has nodoes digitnot ofcontain 3the indigit it3.
a(3) = 1 since the decimal3 representationappears ofonce 3in hasthe onedecimal digitexpansion of 3 in it.
a(3) = 2 since the decimal representation of 33 has two digits of 3 in it.
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| EXTENSIONS
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See my changes to A316863 and make similar changes here - and then delete this line
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#12 by N. J. A. Sloane at Fri Aug 03 18:03:04 EDT 2018
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| EXTENSIONS
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See my changes to A316863 and make similar changes here - and then delete this line
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| STATUS
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proposed
editing
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#11 by Michel Marcus at Fri Jul 20 12:34:43 EDT 2018
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#10 by Michel Marcus at Fri Jul 20 12:34:18 EDT 2018
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| CROSSREFS
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Cf. A000027, A001477.
Cf. A043501, A043502, A043503, A043504.
Cf. A000027, A001477, A055641, A268643, A316864, A316865, A316866, A316867, A316868, A316869, A102683.
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Discussion
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Fri Jul 20
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| Michel Marcus: still not convinced by A000027, A001477.
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