A143655 Triangle read by rows, primes not dividing n; A054521 * (A061397 * 0^(n-k)), 1<=k<=n.

0, 0, 0, 0, 2, 0, 0, 0, 3, 0, 0, 2, 3, 0, 0, 0, 0, 0, 0, 5, 0, 0, 2, 3, 0, 5, 0, 0, 0, 0, 3, 0, 5, 0, 7, 0, 0, 2, 0, 0, 5, 0, 7, 0, 0, 0, 0, 3, 0, 0, 0, 7, 0, 0, 0, 0, 2, 3, 0, 5, 0, 7, 0, 0, 0, 0, 0, 0, 0, 0, 5, 0, 7, 0, 0, 0, 11, 0, 0, 2, 3, 0, 5, 0, 7, 0, 0, 0, 11, 0, 0, 0, 0, 3, 0, 5, 0, 0, 0, 0, 0, 11, 0

Offset

1,5

Comments

Row sums = A066911: (0, 0, 2, 3, 5, 5, 10, 15, 14,....)

Links

Table of n, a(n) for n=1..103.

Formula

Triangle read by rows, A054521 * (A061397 * 0^(n-k)), 1<=k<=n. T(n,k) = prime if k is prime but does not divide n. A054521 = a triangle with row sums phi(n). A061397 = (0, 2, 3, 0, 5, 0, 7,...)

Example

First few rows of the triangle =
0;
0, 0;
0, 2, 0;
0, 0, 3, 0;
0, 2, 3, 0, 0;
0, 0, 0, 0, 5, 0;
0, 2, 3, 0, 5, 0, 0;
0, 0, 3, 0, 5, 0, 7, 0;
...
Row 8 has 3 primes < 8 not dividing 8: (3, 5, 7); where (3 + 5 + 7) = A066911(8).

Crossrefs

Cf. A061397, A066911, A054521.

Sequence in context: A035444 A244141 A152489 * A173541 A333767 A325165

Adjacent sequences: A143652 A143653 A143654 * A143656 A143657 A143658

Keyword

nonn,tabl

Author

Gary W. Adamson, Aug 28 2008

Status

approved