0,5

Row sums of the unsigned triangle = A082480: (1, 2, 4, 12, 48, 288, 2592,...). Right border starting with row 1 (unsigned) = A003266: (1, 1, 2, 6, 30, 240,...).

Triangle read by rows, n-th row = n-th degree polynomial as product of (x-F1)*(x-F2)*(x-F3)*...(x-Fn). n-th row = charpoly of an nxn matrix with F1, F2, F3,...Fn as the diagonal and the rest zeros.

First few rows of the unsigned triangle =

1;

1, 1;

1, 2, 1;

1, 4, 5, 2;

1, 7, 17, 17, 6;

1, 12, 52, 102, 91, 30;

1, 20, 148, 518, 907, 758, 240;

1, 33, 408, 2442, 7641, 12549, 10094, 3120;

1, 54, 1101, 11010, 58923, 173010, 273623, 215094, 65520;

...

Example: row 5 as a signed polynomial = x^5 - 12x^4 + 52x^3 - 102x^2 + 91x - 30.

= (x-1)*(x-1)*(x-2)*(x-3)*(x-5)

A000045, A082480, A003266

Sequence in context: A144460 A057785 A158471 this_sequence A118686 A102610 A134172

Adjacent sequences: A158469 A158470 A158471 this_sequence A158473 A158474 A158475

tabl,sign

Gary W. Adamson (qntmpkt(AT)yahoo.com), Mar 20 2009