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A281012 Zig-zag path that we can find descending by the main diagonal of the pyramid described in A245092. 3
1, 1, 1, 2, 1, 2, 2, 2, 1, 1, 1, 3, 2, 3, 2, 1, 1, 2, 1, 2, 2, 4, 2, 1, 1, 3, 2, 2, 2, 2, 1, 3, 2, 1, 1, 4, 2, 2, 2, 3, 2, 3, 2, 1, 1, 1, 1, 4, 2, 2, 2, 4, 2, 3, 2, 1, 1, 2, 2, 4, 2, 2, 3, 5, 2, 3, 2, 1, 1, 3, 2, 4, 2, 2, 2, 1, 2, 5, 2, 2, 1, 1, 2, 1, 1, 4, 2, 4, 2, 2, 2, 2, 2, 5, 2, 3, 4, 1, 1, 5, 2, 2, 1, 2 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,4

COMMENTS

The odd-indexed terms are the widths of the successive terraces in the main diagonal of the pyramid.

Conjecture: the odd-indexed terms give A281007, the positive terms in A067742.

The even-indexed terms are the precipices from the successive terraces, descending by the main diagonal of the pyramid.

The even-indexed terms give A280919, the first differences of A071562.

The structure of the pyramid arises after the 90-degree-zig-zag folding of the diagram of the isosceles triangle A237593 (see links).

The mentioned pyramid is also a 3D-quadrant of the pyramid described in A244050.

LINKS

Table of n, a(n) for n=1..104.

Omar E. Pol, A pyramid related to the sum-of-divisors function and other integers sequences

Omar E. Pol, Diagram of the isosceles triangle A237593 before the 90-degree-zig-zag folding (rows: 1..28)

Omar E. Pol, Perspective view of the pyramid (first 16 levels)

CROSSREFS

Also A281007 and A280919 interleaved (conjectured).

Cf.  A067742, A071562, A196020, A235791, A236104, A237048, A237270, A237271, A237591, A237593, A244050, A245092, A262626, A279387, A280223.

Sequence in context: A026513 A106028 A105307 * A304943 A248597 A082071

Adjacent sequences:  A281009 A281010 A281011 * A281013 A281014 A281015

KEYWORD

nonn

AUTHOR

Omar E. Pol, Feb 11 2017

STATUS

approved

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Last modified January 22 04:27 EST 2020. Contains 331133 sequences. (Running on oeis4.)