A368127 -id:A368127 - cp's OEIS frontend

A368128 a(n) is the y-coordinate of the n-th point in a square spiral mapped to a square grid rotated by Pi/4 using the symmetrized variant of the distance-limited strip bijection described in A368126.

0, 1, 1, 1, 0, -1, -1, -1, 0, 0, 1, 2, 3, 2, 2, 1, 0, 0, -1, -2, -3, -2, -2, -1, 0, 1, 2, 2, 3, 3, 4, 3, 3, 2, 2, 1, 0, -1, -2, -2, -3, -3, -4, -3, -3, -2, -2, -1, 0, 1, 1, 2, 3, 4, 4, 5, 6, 5, 4, 4, 3, 2, 1, 0, 0, -1, -1, -2, -3, -4, -4, -5, -6, -5, -4, -4, -3, -2, -1, 0, 0, 1, 2, 2, 3, 4

Offset: 0

Hugo Pfoertner, Jan 07 2024

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Hugo Pfoertner, Table of n, a(n) for n = 0..3000
Index entries for sequences related to coordinates of 2D curves

A368127 gives the corresponding x-coordinates.

Cf. A367150, A368126.

\\ Identical to a368127(n), but with
a368128(n) = BijectionD([ax(n), ay(n)], Bijectionk)[2];

A368122 a(n) is the x-coordinate of the n-th point in a square spiral mapped to a square grid rotated by Pi/4 using the symmetrized variant of the distance-limited strip bijection described in A368121.

Original entry on oeis.org

0, 1, 0, -1, -1, -1, 0, 1, 1, 2, 2, 1, 0, 0, -1, -2, -3, -2, -2, -1, 0, 0, 1, 2, 3, 3, 3, 2, 2, 1, 0, -1, -2, -2, -3, -3, -4, -3, -3, -2, -2, -1, 0, 1, 2, 2, 3, 3, 4, 5, 4, 4, 3, 2, 1, 1, 0, 0, -1, -2, -3, -4, -4, -5, -6, -5, -4, -4, -3, -2, -1, -1, 0, 0, 1, 2, 3, 4, 4, 5, 6, 6, 5, 5, 5, 4

Offset: 0

Hugo Pfoertner, Jan 06 2024

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Hugo Pfoertner, Table of n, a(n) for n = 0..3000
Hugo Pfoertner, Plot of mapped spiral, using Plot 2.
Index entries for sequences related to coordinates of 2D curves

A368123 gives the corresponding y-coordinates.
Cf. A367150, A368121, A368127, A368128.
Analogous pair of sequences, but without symmetrization: A367895, A367896.

\\ ax(n), ay(n) after Kevin Ryde's functions in A174344 and A274923.
\\ It is assumed that the PARI programs from A367150 and A368121 have been loaded and the functions defined there are available.
ax(n) = {my (m=sqrtint(n), k=ceil(m/2)); n -= 4*k^2; if (n<0, if (n<-m, k, -k-n), if (n

cp's OEIS Frontend

A368128 a(n) is the y-coordinate of the n-th point in a square spiral mapped to a square grid rotated by Pi/4 using the symmetrized variant of the distance-limited strip bijection described in A368126.

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