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A229951 Number of toothpicks added at n-th stage to the toothpick structure of A229950. 5
0, 0, 0, 1, 0, 1, 0, 1, 0, 2, 1, 2, 0, 2, 1, 2, 0, 2, 1, 3, 1, 3, 2, 3, 0, 3, 2, 3, 1, 3, 1, 3, 1, 4, 3, 4, 1, 4, 3, 4, 1, 4, 2, 4, 2, 4, 3, 4, 0, 4, 3, 5, 3, 5, 3, 5, 2, 5, 4, 5, 1, 5, 4, 5, 2, 5, 3, 5, 3, 5, 3, 5, 1, 6, 5, 6, 4, 6, 4, 6, 2, 6, 5, 6, 2, 6, 5 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,10

COMMENTS

Essentially the first differences of A229950.

Also [0, 0, 0] together the row sums of triangle A229940.

The toothpick structure has the property that the number of exposed endpoints in the row 2k equals the number of divisors of k, if 1<2k<n, k>=1. See example and Link section.

LINKS

Table of n, a(n) for n=0..86.

Omar E. Pol, Illustration of initial terms of the divisor function (A000005), see the third picture.

N. J. A. Sloane, Catalog of Toothpick and Cellular Automata Sequences in the OEIS

Index entries for sequences related to toothpick sequences

EXAMPLE

Illustration of initial terms:

----------------------------------------

n      a(n)       Diagram       A000005

----------------------------------------

0       0

1       0

2       0                          1

3       1         |

4       0                          2

5       1         |

6       0                          2

7       1         |

8       0                          3

9       2         | |

10      1           |              2

11      2         | |

12      0                          4

13      2         | |

14      1           |              2

15      2         | |

16      0                          4

17      2         | |

18      1           |              3

19      3         | | |

20      1             |            4

21      3         | | |

22      2           | |            2

23      3         | | |

24      0                          6

25      3         | | |

26      2           | |            2

27      3         | | |

28      1             |            4

29      3         | | |

30      1           |              4

31      3         | | |

32      1             |            5

33      4         | | | |

...

CROSSREFS

Cf. A000005, A139250, A139251, A229940, A229942, A229950.

Sequence in context: A033794 A218856 A101665 * A165034 A193347 A115862

Adjacent sequences:  A229948 A229949 A229950 * A229952 A229953 A229954

KEYWORD

nonn,tabf

AUTHOR

Omar E. Pol, Oct 04 2013

STATUS

approved

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Last modified February 28 23:19 EST 2020. Contains 332353 sequences. (Running on oeis4.)