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A244677 The spiral of Champernowne, read along the East ray.

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%I A244677 #21 Aug 18 2018 08:33:13
%S A244677 1,2,0,1,1,4,8,9,1,1,6,8,2,4,8,3,6,0,4,9,5,6,6,1,7,4,1,9,0,1,1,1,7,1,
%T A244677 4,7,6,1,6,6,7,1,0,9,0,2,3,5,5,2,7,4,2,3,1,6,1,3,5,1,2,3,0,9,5,4,5,1,
%U A244677 0,4,1,6,7,5,6,4,6,6,3,5,7,6,9,0,0,7,6,8,5,8,3,9,2,8,0,3,1,9,8,0,0,3,0,4,1
%N A244677 The spiral of Champernowne, read along the East ray.
%C A244677 Inspired by Stanislaw Ulam's spiral, circa 1963.
%H A244677 Robert G. Wilson v, <a href="/A244677/a244677.jpg">Cover of the March 1964 issue of Scientific American</a>
%F A244677 Formulas for rays in directions of 32 compass points:
%F A244677   SE     4n^2   -4n  +1
%F A244677   SExS  64n^2 -113n +50
%F A244677   SSE   16n^2  -25n +10
%F A244677   SxE   64n^2 -115n +52
%F A244677   S      4n^2   -5n  +2
%F A244677   SxW   64n^2 -117n +54
%F A244677   SSW   16n^2  -27n +12
%F A244677   SWxS  64n^2 -119n +56
%F A244677   SW     4n^2   -6n  +3
%F A244677   SWxW  64n^2 -121n +58
%F A244677   WSW   16n^2  -29n +14
%F A244677   WxS   64n^2 -123n +60
%F A244677   W      4n^2   -7n  +4
%F A244677   WxN   64n^2 -125n +62
%F A244677   WNW   16n^2  -31n +16
%F A244677   NWxW  64n^2 -127n +64
%F A244677   NW     4n^2   -8n  +5
%F A244677   NWxN  64n^2 -129n +66
%F A244677   NNW   16n^2  -33n +18
%F A244677   NxW   64n^2 -131n +68
%F A244677   N      4n^2   -9n  +6
%F A244677   NxE   64n^2 -133n +70
%F A244677   NNE   16n^2  -35n +20
%F A244677   NExN  64n^2 -135n +72
%F A244677   NE     4n^2  -10n  +7
%F A244677   NExE  64n^2 -137n +74
%F A244677   ENE   16n^2  -37n +22
%F A244677   ExN   64n^2 -139n +76
%F A244677   E      4n^2  -11n  +8
%F A244677   ExS   64n^2 -141n +78
%F A244677   ESE   16n^2  -39n +24
%F A244677   SExE  64n^2 -143n +80
%e A244677 The beginning of the infinite spiral of David Gawen Champernowne:
%e A244677 .
%e A244677   7--1--9--6--1--8--6--1--7--6--1--6--6--1--5--6--1--4--6--1--3  .
%e A244677   |                                                           |  |
%e A244677   0  1--4--4--1--3--4--1--2--4--1--1--4--1--0--4--1--9--3--1  6  .
%e A244677   |  |                                                     |  |  |
%e A244677   1  4  2--1--1--2--1--0--2--1--9--1--1--8--1--1--7--1--1  8  1  .
%e A244677   |  |  |                                               |  |  |  |
%e A244677   7  5  2  0--1--1--0--1--0--0--1--9--9--8--9--7--9--6  6  3  2  9
%e A244677   |  |  |  |                                         |  |  |  |  |
%e A244677   1  1  1  2  7--7--6--7--5--7--4--7--3--7--2--7--1  9  1  1  6  8
%e A244677   |  |  |  |  |                                   |  |  |  |  |  |
%e A244677   1  4  2  1  7  5--5--4--5--3--5--2--5--1--5--0  7  5  1  7  1  1
%e A244677   |  |  |  |  |  |                             |  |  |  |  |  |  |
%e A244677   7  6  3  0  8  5  7--3--6--3--5--3--4--3--3  5  0  9  5  3  1  8
%e A244677   |  |  |  |  |  |  |                       |  |  |  |  |  |  |  |
%e A244677   2  1  1  3  7  6  3  3--2--2--2--1--2--0  3  9  7  4  1  1  6  8
%e A244677   |  |  |  |  |  |  |  |                 |  |  |  |  |  |  |  |  |
%e A244677   1  4  2  1  9  5  8  2  3--1--2--1--1  2  2  4  9  9  1  6  1  1
%e A244677   |  |  |  |  |  |  |  |  |           |  |  |  |  |  |  |  |  |  |
%e A244677   7  7  4  0  8  7  3  4  1  5--4--3  1  9  3  8  6  3  4  3  0  7
%e A244677   |  |  |  |  |  |  |  |  |  |     |  |  |  |  |  |  |  |  |  |  |
%e A244677   3  1  1  4  0  5  9  2  4  6  1--2  0  1  1  4  8  9  1  1  6  8
%e A244677   |  |  |  |  |  |  |  |  |  |        |  |  |  |  |  |  |  |  |  |
%e A244677   1  4  2  1  8  8  4  5  1  7--8--9--1  8  3  7  6  2  1  5  1  1
%e A244677   |  |  |  |  |  |  |  |  |              |  |  |  |  |  |  |  |  |
%e A244677   7  8  5  0  1  5  0  2  5--1--6--1--7--1  0  4  7  9  3  3  9  6
%e A244677   |  |  |  |  |  |  |  |                    |  |  |  |  |  |  |  |
%e A244677   4  1  1  5  8  9  4  6--2--7--2--8--2--9--3  6  6  1  1  1  5  8
%e A244677   |  |  |  |  |  |  |                          |  |  |  |  |  |  |
%e A244677   1  4  2  1  2  6  1--4--2--4--3--4--4--4--5--4  6  9  1  4  1  1
%e A244677   |  |  |  |  |  |                                |  |  |  |  |  |
%e A244677   7  9  6  0  8  0--6--1--6--2--6--3--6--4--6--5--6  0  2  3  8  5
%e A244677   |  |  |  |  |                                      |  |  |  |  |
%e A244677   5  1  1  6  3--8--4--8--5--8--6--8--7--8--8--8--9--9  1  1  5  8
%e A244677   |  |  |  |                                            |  |  |  |
%e A244677   1  5  2  1--0--7--1--0--8--1--0--9--1--1--0--1--1--1--1  3  1  1
%e A244677   |  |  |                                                  |  |  |
%e A244677   7  0  7--1--2--8--1--2--9--1--3--0--1--3--1--1--3--2--1--3  7  4
%e A244677   |  |                                                        |  |
%e A244677   6  1--5--1--1--5--2--1--5--3--1--5--4--1--5--5--1--5--6--1--5  8
%e A244677   |                                                              |
%e A244677   1--7--7--1--7--8--1--7--9--1--8--0--1--8--1--1--8--2--1--8--3--1
%t A244677 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_] := 4n^2 - 11n + 8 (* see formula section *); Array[ almostNatural[ f@#, 10] &, 105]
%Y A244677 Cf. A033307, A054552, A244678 - A244688, A033952, A244690 - A244692.
%K A244677 nonn,easy
%O A244677 1,2
%A A244677 _Robert G. Wilson v_, Jul 04 2014