A342627 Second differences of the y-coordinates of the vertices of the Babylonian Wurm.

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

Offset: 1

Author

James Rayman, Apr 18 2021

Keywords

• sign
• easy

Comments

Equivalently, the first differences of A342625.

Links

• James Rayman, Table of n, a(n) for n = 1..10000
• Index entries for sequences related to coordinates of 2D curves

Crossrefs

See A256175 for the definition of the Babylonian Wurm.

See A342622 and A342623 for the coordinates of the Wurm.

See A342624 and A342625 for the first differences.

See A342626 for the second differences of the x-coordinates.

Programs

Python

for i in range(10000): print(i+1, wurm(i+2)[1] - 2*wurm(i+1)[1] + wurm(i)[1]) # wurm is defined in the program for A256175

Formula

a(n) = A342623(n+2) - 2*A342623(n+1) + A342623(n).