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Write n in base 4 and juxtapose.
27

%I #47 Oct 06 2022 11:37:37

%S 1,2,3,1,0,1,1,1,2,1,3,2,0,2,1,2,2,2,3,3,0,3,1,3,2,3,3,1,0,0,1,0,1,1,

%T 0,2,1,0,3,1,1,0,1,1,1,1,1,2,1,1,3,1,2,0,1,2,1,1,2,2,1,2,3,1,3,0,1,3,

%U 1,1,3,2,1,3,3,2,0,0,2,0,1,2,0,2,2,0,3,2,1,0

%N Write n in base 4 and juxtapose.

%C An irregular table in which the n-th row lists the base-4 digits of n. - _Jason Kimberley_, Nov 26 2012

%C The base-4 Champernowne constant: it is normal in base 4. - _Jason Kimberley_, Nov 26 2012

%H F. J. Aragon Artacho, D. H. Bailey, J. M. Borwein, and P. B. Borwein, <a href="https://carma.newcastle.edu.au/walks/publications.html">Walking on real numbers</a>, preprint September 2012.

%e 1;

%e 2;

%e 3;

%e 1,0;

%e 1,1;

%e 1,2;

%e 1,3;

%e 2,0;

%e 2,1;

%e 2,2;

%e ...

%e 3,3;

%e 1,0,0;

%e 1,0,1;

%e 1,0,2;

%e 1,0,3;

%e 1,1,0; ....

%t Flatten[IntegerDigits[Range[40],4]] (* _Harvey P. Dale_, Aug 23 2011 *)

%o (Magma) &cat[Reverse(IntegerToSequence(n,4)):n in[1..31]]; // _Jason Kimberley_, Dec 07 2012

%o (Python)

%o from itertools import count, chain, islice

%o from sympy.ntheory.factor_ import digits

%o def A030373_gen(): return chain.from_iterable(digits(m, 4)[1:] for m in count(1))

%o A030373_list = list(islice(A030373_gen(), 30)) # _Chai Wah Wu_, Jan 07 2022

%Y Cf. A007376, A003137, A007090.

%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), this sequence (b=4), A031219 (b=5), A030548 (b=6), A030998 (b=7), A031035 and A054634 (b=8), A031076 (b=9), A007376 and A033307 (b=10). - _Jason Kimberley_, Dec 06 2012

%K nonn,base,cons,tabf,easy

%O 1,2

%A _Clark Kimberling_