A187566 Let A be the infinite lower triangular Toplitz matrix with Sigma(n) in every column; and B the diagonalized, signed variant of A002040 with the rest zeros. Sequence gives the triangle in the lower half of A*B read by rows.

1, 3, -2, 4, -6, 4, 7, -8, 12, -8, 6, -14, 16, -24, 21, 12, -12, 28, -32, 63, -52, 8, -24, 24, -56, 84, -156, 131, 15, -16, 48, -48, 147, -208, 393, -316, 13, -30, 32, -96, 126, -364, 524, -948, 765, 18, -26, 60, -64, 252, -312, 917, -1264, 2295, -1846

Offset

0,2

Comments

Row sums = A000041, left border = A000203, main diagonal = A002040 (signed)

Equivalent to the statement that Sigma(n) convolved with A002040(signed +-+-+-...) = the partition numbers; such that (1 + 3x + 4x^2 +7x^3 + ...)*(1 -2x + 4x^2 - 8x^3 + ...) = (1 + x + 2x^2 + 3x^3 + 5x^4 + 7x^5 + ...).

A002040 = (1, 2, 4, 8, 21, 52, 131, 316, 765,...)

Links

Table of n, a(n) for n=0..54.

Example

First few rows of the triangle =
1
3, -2
4, -6, 4
7, -8, 12, -8
6, -14, 16, -24, 21
12, -12, 28, -32, 63, -52
8, -24, 24, -56, 84, -156, 131
15, -16, 48, -48, 147, -208, 393, -316
13, -30, 32, -96, 126, -364, 524, -948, 765
18, -26, 60, -64, 252, -312, 917, -1264, 2295, -1846
...

Crossrefs

Cf. A002040, A000203, A000041

Sequence in context: A319073 A129601 A340579 * A049831 A186005 A080782

Adjacent sequences: A187563 A187564 A187565 * A187567 A187568 A187569

Keyword

tabl,sign

Author

Gary W. Adamson, Mar 18 2011

Status

approved