A082002 - OEIS

A082002

Square array read by antidiagonals, alternating upwards and downwards: T(1, 1) = 1 and every other entry is the smallest number not already used that has a common factor with every number in its row and column, not including the 1.

1, 2, 3, 6, 12, 4, 8, 18, 10, 9, 15, 24, 14, 30, 16, 20, 36, 22, 42, 40, 21, 27, 28, 48, 54, 26, 45, 32, 34, 60, 50, 66, 70, 56, 72, 33, 39, 44, 78, 84, 80, 75, 38, 51, 46, 52, 69, 68, 90, 96, 98, 102, 88, 104, 57, 63, 76, 108, 110, 114, 105, 100, 120, 92, 117, 58, 62, 87, 126

(list; table; graph; refs; listen; history; text; internal format)

OFFSET

1,2

COMMENTS

This is the boustrophedon method of filling an array.

LINKS

Table of n, a(n) for n=1..69.

EXAMPLE

1, 2, 4, 8, 14, 16, ...

3, 12, 18, 24, ...

6, 10, 20, ...

9, 30, ...