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A332247
a(n) is the Y-coordinate of the n-th point of the Minkowski sausage (or Minkowski curve). Sequence A332246 gives X-coordinates.
2
0, 0, 1, 1, 0, -1, -1, 0, 0, 1, 1, 2, 2, 2, 3, 3, 4, 4, 5, 5, 4, 3, 3, 4, 4, 3, 3, 2, 2, 2, 1, 1, 0, -1, -1, -2, -2, -2, -3, -3, -4, -4, -3, -3, -4, -5, -5, -4, -4, -3, -3, -2, -2, -2, -1, -1, 0, 0, 1, 1, 0, -1, -1, 0, 0, 1, 1, 2, 2, 2, 3, 3, 4, 4, 3, 3, 4, 5
OFFSET
0,12
COMMENTS
This sequence is the imaginary part of {f(n)} defined as:
- f(0) = 0,
- f(n+1) = f(n) + i^t(n)
where t(n) is the number of 1's and 6's minus the number of 3's and 4's
in the base 8 representation of n
and i denotes the imaginary unit.
FORMULA
a(8^k-m) = -a(m) for any k >= 0 and m = 0..8^k.
PROG
(PARI) { dd = [0, 1, 0, -1, -1, 0, 1, 0]; z=0; for (n=0, 77, print1 (imag(z)", "); z += I^vecsum(apply(d -> dd[1+d], digits(n, #dd)))) }
CROSSREFS
Cf. A332246 (X-coordinates and additional comments).
Sequence in context: A025778 A294622 A078451 * A341168 A071824 A224921
KEYWORD
sign,look,base
AUTHOR
Rémy Sigrist, Feb 08 2020
STATUS
approved