%I #7 Mar 13 2015 23:22:38

%S 1,1,8,5,9,3,1,0,9,3,3,1,6,8,1,9,1,4,2,1,2,9,7,1,9,4,2,2,2,9,9,3,1,3,

%T 7,3,6,7,6,4,7,1,5,5,4,4,6,6,7,6,7,8,6,9,0,9,1,0,0,4,0,1,4,1,9,2,6,9,

%U 3,4,3,3,6,4,9,5,0,4,6,4,7,9,3,8,9,9,9,3,0,4,1,0,5,2,9,3,3,7,5,4,6,6,1,7,9

%N The hexagonal spiral of Champernowne, read along the North (or 360-degree) ray.

%F (12n^2 - 25n + 14)th almost natural number (A033307), Also see formula section of A056105.

%e see A244807 example section for its diagram.

%t 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 - 25n + 14 (* see formula section of A244807 *); Array[ almostNatural[ f@#, 10] &, 105]

%Y Cf. A007376, A244803, A244807, A244808, A244809, A244811, A244812, A244813, A244814, A244815, A244816, A244817, A244818.

%K nonn,easy

%O 1,3

%A _Robert G. Wilson v_, Jul 06 2014