A079422 a(n) = number of 1's in the first n^2 Spiro-Fibonacci differences.

0, 3, 7, 11, 15, 19, 24, 26, 32, 41, 49, 55, 61, 67, 75, 78, 83, 111, 119, 135, 139, 155, 160, 168, 182, 217, 229, 249, 259, 279, 293, 303, 312, 342, 399, 454, 493, 530, 566, 603, 642, 681, 722, 765, 817, 875, 909, 958, 992, 1044, 1107, 1160, 1215, 1267, 1315

Offset

1,2

Links

Table of n, a(n) for n=1..55.

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

Example

The Spiro-Fibonacci differences are 0,1,1,1,1,1,1,1,0,1,0,1,0,1,0,1,...(A079421). Terms are written in square boxes radiating spirally. a(n) = the sum of the first n^2 terms in A079421, i.e. the number of 1's in a spiral of height n and width n.

Crossrefs

Cf. A063826, A078510, A079421.

Sequence in context: A039957 A217332 A369056 * A310210 A292657 A277675

Adjacent sequences: A079419 A079420 A079421 * A079423 A079424 A079425

Keyword

nonn

Author

Neil Fernandez, Jan 07 2003

Extensions

More terms from Sean A. Irvine, Aug 13 2025

Status

approved