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A139438 Frieze pattern with 5 rows, read by diagonals. 2
1, 1, 2, 3, 1, 1, 3, 5, 2, 1, 1, 2, 1, 1, 1, 1, 1, 2, 3, 1, 1, 3, 5, 2, 1, 1, 2, 1, 1, 1, 1, 1, 2, 3, 1, 1, 3, 5, 2, 1, 1, 2, 1, 1, 1, 1, 1, 2, 3, 1, 1, 3, 5, 2, 1, 1, 2, 1, 1, 1, 1, 1, 2, 3, 1, 1, 3, 5, 2, 1, 1, 2, 1, 1, 1, 1, 1, 2, 3, 1, 1, 3, 5, 2, 1, 1, 2, 1, 1, 1, 1, 1, 2, 3, 1, 1, 3, 5, 2 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,3

COMMENTS

Period 15: repeat [1, 1, 2, 3, 1, 1, 3, 5, 2, 1, 1, 2, 1, 1, 1]. - Wesley Ivan Hurt, Jun 05 2016

LINKS

Table of n, a(n) for n=0..98.

James Propp, The combinatorics of frieze patterns and Markoff numbers, arXiv:math/0511633v4.

FORMULA

Four adjacent entries

...A...

.B...C.

...D...

satisfy D = (BC-1)/A.

EXAMPLE

The frieze pattern is

... 1 1 1 1 1 1 1 ...

.....1 3 2 1 3 2 ...

....1 2 5 1 2 5 1 ...

.....1 3 2 1 3 2 ...

... 1 1 1 1 1 1 1 ...

CROSSREFS

Cf. A139434, A139458.

Sequence in context: A141071 A004648 A265848 * A135392 A071947 A139343

Adjacent sequences:  A139435 A139436 A139437 * A139439 A139440 A139441

KEYWORD

nonn,tabf

AUTHOR

N. J. A. Sloane, Jun 09 2008

STATUS

approved

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Last modified December 6 04:14 EST 2019. Contains 329784 sequences. (Running on oeis4.)