A178937 Partial sums of number of different shapes formed by bending a piece of wire of length n in the plane A066372.

1, 2, 4, 7, 12, 20, 35, 58, 101, 172, 300, 509, 888, 1538, 2683, 4611, 8033, 13941, 24236, 41766, 72504, 125592, 217563, 374757, 648378, 1120243, 1934800, 3328622, 5743517, 9901009, 17061027, 29314809, 50478219, 86859244, 149408560, 256438542, 440869300

Offset

1,2

Comments

Number of different shapes formed by bending (+ or - 90 degrees at each bend) a piece of wire of length <= n in the plane.

Links

Table of n, a(n) for n=1..37.

Example

a(9) = 1 + 1 + 2 + 3 + 5 + 8 + 15 + 23 + 43 = 101 is prime. The next prime is a(15) = 2683.

Mathematica

Cases[Import["https://oeis.org/A066372/b066372.txt", "Table"], {_, _}][[All, 2]] // Accumulate (* Jean-François Alcover, Feb 22 2020 *)

Crossrefs

Cf. A001997, A066372.

Sequence in context: A186537 A079970 A079816 * A168368 A305106 A182746

Adjacent sequences: A178934 A178935 A178936 * A178938 A178939 A178940

Keyword

nonn,walk

Author

Jonathan Vos Post, Dec 30 2010

Extensions

More terms from Nathaniel Johnston, Jan 04 2011

More terms from A066372 by Jean-François Alcover, Feb 22 2020

Status

approved