# Greetings from The On-Line Encyclopedia of Integer Sequences! http://oeis.org/ Search: id:a244677 Showing 1-1 of 1 %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, Cover of the March 1964 issue of Scientific American %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 # Content is available under The OEIS End-User License Agreement: http://oeis.org/LICENSE