A059578 Variation of Boustrophedon transform applied to 1,1,1,1,... Fill an array by diagonals, all in the 'up' direction. The first column is 1,1,1,1,.... For the next element of a diagonal, add to the previous element the elements of the row and the column the new element is in. The first row gives a(n).

1, 2, 7, 30, 147, 792, 4559, 27500, 171645, 1099388, 7185101, 47724494, 321225165, 2186177302, 15018795171, 104011496474, 725373340023, 5089785834004, 35907469451787, 254541483884544, 1812185157383017, 12951828431246472, 92893383046741073, 668383820775639066

Offset

1,2

Links

Table of n, a(n) for n=1..24.

Example

The array begins
1 2 7 30 ...
1 4 20 ...
1 8 ...
1 ...

Crossrefs

Cf. A000667, A035002, A059216, A059219, A059502, A059513.

Sequence in context: A196148 A193464 A166990 * A136574 A290875 A030836

Adjacent sequences: A059575 A059576 A059577 * A059579 A059580 A059581

Keyword

easy,nonn

Author

Floor van Lamoen, Jan 23 2001

Extensions

More terms from Sean A. Irvine, Sep 29 2022

Status

approved