A319772 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 imaginary part of f(n).

0, 1, 1, 0, 0, 2, 2, 3, 3, 0, 6, 2, 0, 1, 3, 4, 4, 3, 7, 1, 2, 3, 5, 4, 4, 1, 3, 9, 4, 1, 8, 6, 0, 8, 5, 2, 2, 11, 7, 1, 4, 5, 6, 8, 1, 7, 6, 2, 3, 5, 7, 10, 2, 5, 6, 0, 0, 2, 6, 5, 9, 6, 6, 4, 7, 9, 1, 4, 13, 1, 12, 5, 8, 14, 9, 8, 4, 9, 3, 7, 11, 0, 3, 7, 6

Offset

1,6

Comments

See A319770 for the square of the modulus of f and additional comments.

Links

Rémy Sigrist, Table of n, a(n) for n = 1..10000

Crossrefs

Cf. A319770.

Sequence in context: A068460 A308120 A143797 * A079729 A288723 A071859

Adjacent sequences: A319769 A319770 A319771 * A319773 A319774 A319775

Keyword

nonn

Author

Rémy Sigrist, Sep 27 2018

Status

approved