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.
LINKS
Rémy Sigrist, Table of n, a(n) for n = 0..4096
Robert Ferréol (MathCurve), Saucisse de Minkowski [in French]
Wikipedia, Minkowski sausage
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
KEYWORD
AUTHOR
Rémy Sigrist, Feb 08 2020
STATUS
approved