1,7

For rows >1, n-th row = all 1's iff n is prime.

Row sums = A156833: (1, 2, 3, 6, 5, 16, 7, 24, 24, 38, 11,...).

Triangle read by rows, A054525 * A156348 * A000012 A054525 = the inverse Mobius transform, A000012 = an infinite lower triangular matrix with all 1's.

First few rows of the triangle =

1;

1, 1;

1, 1, 1;

2, 2, 1, 1;

1, 1, 1, 1, 1;

5, 5, 3, 1, 1, 1;

1, 1, 1, 1, 1, 1, 1;

6, 6, 4, 4, 1, 1, 1, 1;

6, 6, 6, 1, 1, 1, 1, 1, 1;

9, 9, 5, 5, 5, 1, 1, 1, 1, 1;

1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1;

24, 24, 22, 15, 6, 6, 1, 1, 1, 1, 1, 1;

1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1;

13, 13, 7, 7, 7, 7, 7, 1, 1, 1, 1, 1, 1, 1;

...

Cf. A156348, A054525, A156833

Sequence in context: A165735 A083888 A102681 this_sequence A025453 A094215 A114139

Adjacent sequences: A156836 A156837 A156838 this_sequence A156840 A156841 A156842

nonn,tabl

Gary W. Adamson and Mats Granvik (qntmpkt(AT)yahoo.com), Feb 16 2009