A244681 The spiral of Champernowne read by the North ray.

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

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 - 9n + 6 (* see A244677 formula section *); Array[ almostNatural[ f@#, 10] &, 105]

Crossrefs

Cf. A033307, A054556, A033952, A244677 - A244688, A244690 - A244692.

Sequence in context: A217462 A016510 A334232 * A023634 A199609 A284692

Adjacent sequences: A244678 A244679 A244680 * A244682 A244683 A244684

Keyword

nonn,easy

Author

Robert G. Wilson v, Jul 04 2014

Status

approved