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

1,1

Comments

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

Links

Table of n, a(n) for n=1..100.

Example

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;
...

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

Crossrefs

Cf. A051731, A007445, A127639.

Sequence in context: A234808 A248079 A127638 * A248081 A259632 A304041

Adjacent sequences: A127636 A127637 A127638 * A127640 A127641 A127642

Keyword

nonn,tabl,easy

Author

Gary W. Adamson, Jan 21 2007

Extensions

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

Status

approved