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A322575
z(1) = 0, and for any n > 0, z(4*n-2) = z(n) + k(n), z(4*n-1) = z(n) + i*k(n), z(4*n) = z(n) - k(n) and z(4*n+1) = z(n) - i*k(n) where k(n) is the least positive integer not leading to a duplicate term in sequence z (and i denotes the imaginary unit); a(n) is the imaginary part of z(n).
3
0, 0, 1, 0, -1, 0, 3, 0, -3, 1, 4, 1, -2, 0, 3, 0, -3, -1, 2, -1, -4, 0, 1, 0, -1, 3, 4, 3, 2, 0, 8, 0, -8, -3, -2, -3, -4, 1, 5, 1, -3, 4, 13, 4, -5, 1, 2, 1, 0, -2, 5, -2, -9, 0, 7, 0, -7, 3, 7, 3, -1, 0, 11, 0, -11, -3, 2, -3, -8, -1, 4, -1, -6, 2, 10, 2
OFFSET
1,7
LINKS
PROG
(PARI) \\ See Links section.
CROSSREFS
See A322574 for the real part of z and additional comments.
Sequence in context: A318505 A376627 A237595 * A166445 A374139 A298082
KEYWORD
sign,look
AUTHOR
Rémy Sigrist, Dec 17 2018
STATUS
approved