A244687 The spiral of Champernowne read by the Southwest ray.

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

Offset

1,2

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_] := 4n^2 - 6n + 3 (* see A244677 formula section *); Array[ almostNatural[ f@#, 10] &, 105]

Crossrefs

Cf. A033307, A054569, A033952, A244677-A244688, A244690-A244692.

Sequence in context: A233822 A199462 A195847 * A154171 A199442 A280811

Adjacent sequences: A244684 A244685 A244686 * A244688 A244689 A244690

Keyword

nonn,easy

Author

Robert G. Wilson v, Jul 04 2014

Status

approved