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%I #9 Mar 14 2015 11:44:50
%S 1,4,1,1,9,4,9,7,1,1,1,1,1,2,2,2,2,3,3,3,4,4,5,5,6,6,7,7,8,8,9,9,5,9,
%T 4,9,9,0,0,1,7,3,0,6,9,9,4,3,5,7,2,2,5,8,4,4,9,1,0,8,7,6,0,5,9,4,4,4,
%U 5,4,2,5,5,7,4,9,9,2,0,5,7,9,0,4,9,9,4,5,5,1,2,8,5,6,4,4,9,3,0,2,7,2,0,3,9
%N The hexagonal spiral of Champernowne, read along the 330-degree ray.
%F (3n^2 - 6n + 4)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_] := 3n^2 - 6n + 4 (* see formula section of A244807 *); Array[ almostNatural[ f@#, 10] &, 105]
%Y Cf. A007376, A056107, A244807, A244808, A244809, A244810, A244812, A244813, A244814, A244815, A244816, A244817, A244818.
%K nonn,easy
%O 1,2
%A _Robert G. Wilson v_, Jul 06 2014