A079421 Spiro-Fibonacci differences, a(n) = difference of two previous terms that are nearest when terms arranged in a spiral.

0, 1, 1, 1, 1, 1, 1, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 0, 1, 0, 1, 1, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0, 1, 1, 1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 1, 0, 1

Offset

0,1

Links

Table of n, a(n) for n=0..77.

N. Fernandez, Graphical representations of some Spiro-Fibonacci sequences

Example

Terms are written in square boxes radiating spirally (cf. Ulam prime spiral). a(0)=0 and a(1)=1, so write 0 and then 1 to its right. a(2) goes in the box below a(1). The nearest two filled boxes contain a(0) and a(1), so a(2)=abs(a(0)-a(1))=abs(0-1)=1. a(3) goes in the box to the left of a(2). The nearest two filled boxes contain a(0) and a(2), so a(3)=abs(a(0)-a(2))=abs(0-1)=1.

Crossrefs

Cf. A063826, A078510.

Sequence in context: A109720 A022932 A334812 * A304438 A168181 A368916

Adjacent sequences: A079418 A079419 A079420 * A079422 A079423 A079424

Keyword

nonn

Author

Neil Fernandez, Jan 07 2003

Status

approved