A308897 Walk a rook along the square spiral numbered 1, 2, 3, ... (cf. A274640); a(n) = mex of earlier values the rook can move to.

1, 2, 1, 2, 3, 4, 1, 3, 4, 2, 3, 4, 1, 3, 4, 2, 5, 6, 7, 8, 1, 5, 6, 7, 8, 2, 5, 6, 7, 8, 1, 5, 6, 7, 8, 2, 3, 6, 5, 8, 7, 4, 1, 3, 6, 5, 8, 7, 4, 2, 3, 6, 5, 8, 7, 4, 1, 3, 6, 5, 8, 7, 4, 2, 9, 10, 11, 12, 13, 14, 15, 16, 1, 9, 10, 11, 12, 13, 14, 15, 16, 2

Offset

1,2

Comments

Mex here means "smallest positive missing number".

Add 1 to the terms of A308896.

Links

Table of n, a(n) for n=1..82.

Crossrefs

Cf. A274640, A308896.

Sequence in context: A255560 A328472 A046653 * A353293 A162190 A349325

Adjacent sequences: A308894 A308895 A308896 * A308898 A308899 A308900

Keyword

nonn

Author

N. J. A. Sloane, Jul 02 2019

Extensions

More terms from Rémy Sigrist, Jul 02 2019

Status

approved