0,5

Right border = A001710 starting (1, 1, 3, 12, 60, 360, 2520,...) Row sums = n!: (1, 2, 6, 24,...). Example: 24 = 4! = (1 + 3 + 8 + 12). Each term in n-th row divides n!.

Given triangle A130461 and deleting the left border (1,1,1,...)take finite differences by columns and reorient into rows.

First few rows of the triangle A130461 = (1; 1, 1; 1, 1, 1; 1, 1, 2, 1; 1, 1, 2, 3, 1; 1, 1, 2, 6, 4, 1;...). Deleting the left border and taking finite differences at the top of each remaining column, we get the first few rows of triangle A130477:

1;

1, 1;

1, 2, 3;

1, 3, 8, 12;

1, 4, 15, 40, 60;

1, 5, 24, 90, 240, 360,

1, 6, 35, 168, 630, 1680, 2520;

...

Cf. A130460, A130461, A130476, A130478.

Sequence in context: A121424 A093768 A119011 this_sequence A058127 A133935 A139633

Adjacent sequences: A130474 A130475 A130476 this_sequence A130478 A130479 A130480

nonn,tabl

Gary W. Adamson (qntmpkt(AT)yahoo.com), May 28 2007