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 A244818 #9 Nov 04 2023 13:14:08
%S A244818 1,1,6,7,1,8,1,4,1,3,6,6,6,4,3,9,3,7,2,1,2,3,7,1,7,9,3,2,8,5,0,3,5,0,
%T A244818 8,4,8,4,6,4,7,9,6,5,2,3,7,6,3,6,8,8,0,9,1,9,3,9,1,0,0,1,3,1,2,2,1,8,
%U A244818 1,3,4,1,6,1,5,5,1,5,1,7,7,1,7,1,9,9,2,0,2,1,1,2,6,2,3,4,2,3,2,5,6,2,3,2,8
%N A244818 The hexagonal spiral of Champernowne, read along the 120-degree ray.
%F A244818 (12n^2-17n+6)th almost natural number (A033307), also see formula section of A056105.
%e A244818 See A244807 example section for its diagram.
%t A244818 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]]]; f[n_] := 12n^2 - 17n + 6 (* see formula section of A244807 *); Array[ almostNatural[ f@#, 10] &, 105]
%Y A244818 Cf. A007376, A033577, A244807, A244808, A244809, A244810, A244811, A244812, A244813, A244814, A244815, A244816, A244817.
%K A244818 nonn,easy
%O A244818 1,3
%A A244818 _Robert G. Wilson v_, Jul 06 2014