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A319771
Let f(1) = 1, f(2) = 1 + i (where i denotes the imaginary unit), f(3) = 2 + i, and for n > 2, f(n+1) is the Gaussian integer in the first quadrant (with positive real part and nonnegative imaginary part) with least modulus and sharing at least one prime factor with f(n-1) but none with f(n) (in case of a tie, minimize the imaginary part); a(n) = the real part of f(n).
2
1, 1, 2, 2, 5, 2, 1, 1, 4, 4, 3, 4, 3, 3, 6, 2, 3, 3, 4, 5, 3, 2, 1, 7, 4, 8, 5, 2, 1, 4, 2, 7, 6, 1, 3, 9, 6, 2, 1, 12, 6, 2, 2, 9, 7, 6, 4, 11, 7, 10, 3, 5, 5, 5, 15, 8, 9, 8, 9, 7, 6, 1, 6, 13, 5, 8, 6, 8, 4, 9, 1, 4, 4, 3, 1, 11, 5, 3, 14, 7, 8, 7, 9, 14
OFFSET
1,3
COMMENTS
See A319770 for the square of the modulus of f and additional comments.
LINKS
CROSSREFS
Cf. A319770.
Sequence in context: A326914 A374106 A155679 * A021448 A359246 A229709
KEYWORD
nonn
AUTHOR
Rémy Sigrist, Sep 27 2018
STATUS
approved