A173539 Square array read by antidiagonals: T(n,k)=0 if k is a divisor of n, otherwise T(n,k)=k.

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

Offset: 1

Author

Omar E. Pol, May 25 2010

Keywords

• easy
• nonn
• tabl

Comments

Observation: Column k is the sequence defined as: Period k: repeat (k-1 numbers k together with zero).

Note that the positive terms in row n are the non-divisors of n (See also A173540 and A173541).

Examples

			Array begins:
0,2,3,4,5,6,7,8,9,10,11,12;
0,0,3,4,5,6,7,8,9,10,11;
0,2,0,4,5,6,7,8,9,10;
0,0,3,0,5,6,7,8,9;
0,2,3,4,0,6,7,8;
0,0,0,4,5,0,7;
0,2,3,4,5,6;
0,0,3,0,5;
0,2,0,4;
0,0,3;
0,2;
0;
		

Crossrefs

Cf. A007978, A173540, A173541.