This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A031219 #31 Sep 08 2022 08:44:50
%S A031219 1,2,3,4,1,0,1,1,1,2,1,3,1,4,2,0,2,1,2,2,2,3,2,4,3,0,3,1,3,2,3,3,3,4,
%T A031219 4,0,4,1,4,2,4,3,4,4,1,0,0,1,0,1,1,0,2,1,0,3,1,0,4,1,1,0,1,1,1,1,1,2,
%U A031219 1,1,3,1,1,4,1,2,0,1,2,1,1,2,2,1,2,3,1,2,4,1
%N A031219 Write n in base 5 and juxtapose.
%C A031219 An irregular table in which the n-th row lists the base-5 digits of n. - _Jason Kimberley_, Dec 07 2012
%C A031219 The base-5 Champernowne constant: it is normal in base 5. - _Jason Kimberley_, Dec 07 2012
%t A031219 Flatten@ IntegerDigits[ Range@ 40, 5] (* or *)
%t A031219 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[ a[#, 5] &, 105] (* _Robert G. Wilson v_, Jul 01 2014 *)
%o A031219 (Magma) &cat[Reverse(IntegerToSequence(n,5)):n in[1..31]]; // _Jason Kimberley_, Dec 07 2012
%o A031219 (Python)
%o A031219 from itertools import count, chain, islice
%o A031219 from sympy.ntheory.factor_ import digits
%o A031219 def A031219_gen(): return chain.from_iterable(digits(m, 5)[1:] for m in count(1))
%o A031219 A031219_list = list(islice(A031219_gen(), 30)) # _Chai Wah Wu_, Jan 07 2022
%Y A031219 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), this sequence (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 A031219 nonn,base,cons,easy,tabf
%O A031219 1,2
%A A031219 _Clark Kimberling_