A127639 A051731 * A127640, where A127640 = infinite lower triangular matrix with the sequence of primes in the main diagonal and the rest zeros.

2, 2, 3, 2, 0, 5, 2, 3, 0, 7, 2, 0, 0, 0, 11, 2, 3, 5, 0, 0, 13, 2, 0, 0, 0, 0, 0, 17, 2, 3, 0, 7, 0, 0, 0, 19, 2, 0, 5, 0, 0, 0, 0, 0, 23, 2, 3, 0, 0, 11, 0, 0, 0, 0, 29, 2, 0, 0, 0, 0, 0, 0, 0, 0, 0, 31, 2, 3, 5, 7, 0, 13, 0, 0, 0, 0, 0, 37, 2, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 41, 2, 3, 0, 0, 0, 0, 17, 0, 0

Offset: 1

Author

Gary W. Adamson, Jan 21 2007

Keywords

• nonn
• tabl
• easy

Comments

Row sums = A007445, inverse Mobius transform of the primes: (2, 5, 7, 12, 13, 23, ...)

Examples

			First few rows of the triangle are:
2;
2, 3;
2, 0, 5;
2, 3, 0, 7;
2, 0, 0, 0, 11;
2, 3, 5, 0, 0, 13;
...
		

Crossrefs

Cf. A051731, A007445, A127639.

Programs

Maple

A051731 := proc(n,k) if n mod k = 0 then 1 ; else 0 ; fi ; end: A127639 := proc(n,k) A051731(n,k)*ithprime(k) ; end: for n from 1 to 16 do for k from 1 to n do printf("%d,", A127639(n,k)) ; od ; od ; # R. J. Mathar, Mar 14 2007

Extensions

More terms from R. J. Mathar, Mar 14 2007