OEIS/Spirals
Hexagonal grid, counterclockwise
Cf. A056105 First spoke of a hexagonal spiral.
From Robert G. Wilson v, Jul 05 2014: (Start) Each of the 6 primary spokes or rays has a generating formula as stated here: 1st: 90 degrees A056105 3n^2 - 2n + 1 2nd: 30 degrees A056106 3n^2 - n + 1 3rd: 330 degrees A056107 3n^2 + 1 4th: 270 degrees A056108 3n^2 + n + 1 5th: 210 degrees A056109 3n^2 + 2n + 1 6th: 150 degrees A003215 3n^2 + 3n + 1 Each of the 6 secondary spokes or rays has a generating formula as stated here: 1st: 60 degrees 12n^2 - 27n + 16 2nd: 360 degrees 12n^2 - 25n + 14 3rd: 300 degrees 12n^2 - 23n + 12 4th: 240 degrees 12n^2 - 21n + 10 5th: 180 degrees 12n^2 - 19n + 8 6th: 120 degrees 12n^2 - 17n + 6 = A033577(n+1)
Square grid, counterclockwise
Cf. A244677 The spiral of Champernowne, read along the East ray. Robert G. Wilson v, Cover of the March 1964 issue of Scientific American Formulas for rays in directions of 32 compass points:
SE 4n^2 -4n +1 SExS 64n^2 -113n +50 SSE 16n^2 -25n +10 SxE 64n^2 -115n +52 S 4n^2 -5n +2 SxW 64n^2 -117n +54 SSW 16n^2 -27n +12 SWxS 64n^2 -119n +56 SW 4n^2 -6n +3 SWxW 64n^2 -121n +58 WSW 16n^2 -29n +14 WxS 64n^2 -123n +60 W 4n^2 -7n +4 WxN 64n^2 -125n +62 WNW 16n^2 -31n +16 NWxW 64n^2 -127n +64 NW 4n^2 -8n +5 NWxN 64n^2 -129n +66 NNW 16n^2 -33n +18 NxW 64n^2 -131n +68 N 4n^2 -9n +6 NxE 64n^2 -133n +70 NNE 16n^2 -35n +20 NExN 64n^2 -135n +72 NE 4n^2 -10n +7 NExE 64n^2 -137n +74 ENE 16n^2 -37n +22 ExN 64n^2 -139n +76 E 4n^2 -11n +8 ExS 64n^2 -141n +78 ESE 16n^2 -39n +24 SExE 64n^2 -143n +80