A126937 A dragon curve is drawn on an Ulam spiral; a(n) is the integer written in the cell reached at step n.

0, 1, 8, 7, 22, 21, 6, 19, 20, 41, 40, 19, 18, 39, 38, 67, 68, 105, 104, 67, 66, 37, 38, 17, 16, 37, 36, 35, 62, 63, 98, 99, 64, 101, 100, 99, 142, 141, 98, 97, 140, 139, 96, 97, 62, 61, 34, 33, 60, 61, 96, 95, 138, 137, 94, 93, 136, 137, 188, 187, 246, 247, 314, 315, 248

Offset

0,3

Comments

The spiral consists of the numbers 0, 1, 2, ... written in a spiral on squared paper. The dragon curve is a self-similar curve starting at the same point. See the illustration for more information.

Links

Table of n, a(n) for n=0..64.

Philippe Lallouet, Spreadsheet with illustration of initial terms

Eric Weisstein's World of Mathematics, Dragon Curve [From Klaus Brockhaus, Aug 07 2008]

Eric Weisstein's World of Mathematics, Prime Spiral [From Klaus Brockhaus, Aug 07 2008]

Crossrefs

Cf. A014577 (regular paper-folding [or dragon curve] sequence). [From Klaus Brockhaus, Aug 07 2008]

Sequence in context: A166138 A348673 A302512 * A282471 A309877 A303311

Adjacent sequences: A126934 A126935 A126936 * A126938 A126939 A126940

Keyword

nonn

Author

Philippe Lallouet (philip.lallouet(AT)wanadoo.fr), Mar 18 2007

Extensions

Edited by N. J. A. Sloane, Mar 28 2007

a(9) - a(64) from Klaus Brockhaus, Aug 07 2008

Status

approved