A319563 Let f(1) = 1, f(2) = 1 + i (where i denotes the imaginary unit), and for n > 1, f(n+1) is the Gaussian integer in the first quadrant (with positive real part and nonnegative imaginary part) with least modulus and sharing a prime factor with f(n) (in case of a tie, minimize the imaginary part); a(n) = the imaginary part of f(n).

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

Offset

1,4

Comments

See A319561 for the square of the modulus of f and additional comments.

Links

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

Rémy Sigrist, PARI program for A319563

Prog

(PARI) See Links section.

Crossrefs

Cf. A319561.

Sequence in context: A262876 A263045 A333442 * A201912 A201908 A337712

Adjacent sequences: A319560 A319561 A319562 * A319564 A319565 A319566

Keyword

nonn

Author

Rémy Sigrist, Sep 23 2018

Status

approved