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%I #31 Sep 08 2022 08:44:50
%S 1,2,3,4,5,6,7,8,1,0,1,1,1,2,1,3,1,4,1,5,1,6,1,7,1,8,2,0,2,1,2,2,2,3,
%T 2,4,2,5,2,6,2,7,2,8,3,0,3,1,3,2,3,3,3,4,3,5,3,6,3,7,3,8,4,0,4,1,4,2,
%U 4,3,4,4,4,5,4,6,4,7,4,8,5,0,5,1,5,2,5,3,5,4
%N Write n in base 9 and juxtapose.
%C An irregular table in which the n-th row lists the base-9 digits of n. - _Jason Kimberley_, Dec 07 2012
%C The base-9 Champernowne constant: it is normal in base 9. - _Jason Kimberley_, Dec 07 2012
%H Reinhard Zumkeller, <a href="/A031076/b031076.txt">Table of n, a(n) for n = 1..10000</a>
%t Flatten@ IntegerDigits[ Range@ 55, 9] (* or *)
%t almostNatural[n_, b_] := Block[{m = 0, d = n, i = 1, l, p}, While[m <= d, l = m; m = (b - 1) i*b^(i - 1) + l; i++]; i--; p = Mod[d - l, i]; q = Floor[(d - l)/i] + b^(i - 1); If[p != 0, IntegerDigits[q, b][[p]], Mod[q - 1, b]]]; Array[ almostNatural[#, 9] &, 105] (* _Robert G. Wilson v_, Jul 01 2014 *)
%o (Magma) &cat[Reverse(IntegerToSequence(n,9)):n in[1..31]]; // _Jason Kimberley_, Dec 07 2012
%o (Haskell)
%o a031076 n = a031076_list !! (n-1)
%o a031076_list = concat $ map reverse $ tail a031087_tabf
%o -- _Reinhard Zumkeller_, Jul 07 2015
%o (Python)
%o from itertools import count, chain, islice
%o from sympy.ntheory.factor_ import digits
%o def A031076_gen(): return chain.from_iterable(digits(m,9)[1:] for m in count(1))
%o A031076_list = list(islice(A031076_gen(),30)) # _Chai Wah Wu_, Jan 07 2022
%Y Tables in which the n-th row lists the base b digits of n: A030190 and A030302 (b=2), A003137 and A054635 (b=3), A030373 (b=4), A031219 (b=5), A030548 (b=6), A030998 (b=7), A031035 and A054634 (b=8), this sequence (b=9), A007376 and A033307 (b=10). - _Jason Kimberley_, Dec 06 2012
%Y Cf. A031087, A007095.
%K nonn,base,cons,easy,tabf
%O 1,2
%A _Clark Kimberling_
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