A244680 The spiral of Champernowne read by the North-Northeast ray.

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

Offset

1,3

Links

Table of n, a(n) for n=1..105.

Formula

See A244677 formula section.

Example

See A244677 for the spiral of David Gawen Champernowne.

Mathematica

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_] := 16n^2 - 35n + 20 (* see A244677 formula section *); Array[ almostNatural[ f@#, 10] &, 105]

Crossrefs

Cf. A033307, A033952, A143861, A244677 - A244688, A244690 - A244692.

Sequence in context: A135004 A086234 A016490 * A200355 A307868 A021216

Adjacent sequences: A244677 A244678 A244679 * A244681 A244682 A244683

Keyword

nonn,easy

Author

Robert G. Wilson v, Jul 04 2014

Status

approved