0,4

A124072 must be consulted . We change the sign of every negative number and consider the differences of every line. Hence for the second line and followers the four terms periodic sequences:

0 1 -1 1 0

1 0 0 1 1

1 0 1 2 1

1 1 3 3 1

2 4 6 4 2

6 10 10 6 6

16 20 16 12 16

36 36 28 28 36

72 64 56 64 72

136 120 120 136 136

256 240 256 272 256

They are linked together : 272=136+136, 256=120+136, 240=120+120, 256=136+120 . The 4 columns are almost known (must the first line be suppressed?) :A038503 (without the first 1),A000749 (without the first 0),A038505, A038504 G. Adamson (two days ago,I submited 1 1 0 0 without knowing Adamson comment . Like the present one, every sequence of A124072 begining by a negative number (-2,-11..) is a "twisted" sequence (see A129339 comments,A129961 and the present 4 columns) . Periodic 2^n .

Adjacent sequences: A130665 A130666 A130667 this_sequence A130669 A130670 A130671

Sequence in context: A059411 A126017 A034468 this_sequence A083380 A018112 A067149

sign,uned

Paul Curtz (bpcrtz(AT)free.fr), Jun 27 2007