A230847 - OEIS

A230847

a(n) = 1 + A054541(n).

3, 2, 3, 3, 5, 3, 5, 3, 5, 7, 3, 7, 5, 3, 5, 7, 7, 3, 7, 5, 3, 7, 5, 7, 9, 5, 3, 5, 3, 5, 15, 5, 7, 3, 11, 3, 7, 7, 5, 7, 7, 3, 11, 3, 5, 3, 13, 13, 5, 3, 5, 7, 3, 11, 7, 7, 7, 3, 7, 5, 3, 11, 15, 5, 3, 5, 15, 7, 11, 3, 5, 7, 9, 7, 7, 5, 7, 9, 5, 9, 11, 3, 11, 3, 7, 5, 7, 9, 5, 3, 5, 13, 9, 5, 9, 5, 7

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OFFSET

1,1

COMMENTS

Partial sums give A014688.

LINKS

Table of n, a(n) for n=1..97.

FORMULA

a(n) = A230846(n) = A076368(n), n>1. - R. J. Mathar, May 16 2023

EXAMPLE

On the first quadrant of the square grid consider a diagram in which the n-th horizontal bar contains A000040(n) cells and in which the number of cells in the vertical bars gives 0 together with A000720 as shown below. a(n) is the sum of the length of the n-th horizontal boundary segment and the length of the n-th vertical boundary segment between the structure formed by the horizontal bars and the structure formed by the vertical bars, hence a(n) = A054541(n) + 1. The total length of the boundary segments from [0, 0] after n-th stage is A014688(n).

. _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _

31 |_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _|

29 |_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _| | |

23 |_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _| | | | | | | | |

19 |_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _| | | | | | | | | | | | |

17 |_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _| | | | | | | | | | | | | | |

13 |_ _ _ _ _ _ _ _ _ _ _ _ _| | | | | | | | | | | | | | | | | | |

11 |_ _ _ _ _ _ _ _ _ _ _| | | | | | | | | | | | | | | | | | | | |

7 |_ _ _ _ _ _ _| | | | | | | | | | | | | | | | | | | | | | | | |

5 |_ _ _ _ _| | | | | | | | | | | | | | | | | | | | | | | | | | |

3 |_ _ _| | | | | | | | | | | | | | | | | | | | | | | | | | | | |

2 |_ _|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|

. 0 0 1 2 2 3 3 4 4 4 4 5 5 6 6 6 6 7 7 8 8 8 8 9 9 9 9 9 9 10 10

CROSSREFS

Cf. A000040, A014688, A054541, A076368.

Sequence in context: A317623 A286244 A230010 * A234300 A181672 A125748

Adjacent sequences: A230844 A230845 A230846 * A230848 A230849 A230850

KEYWORD

nonn

AUTHOR

Omar E. Pol, Nov 01 2013

STATUS

approved