A090324 Second in a series of triangular arrays generating the natural numbers (cf. A079946).

6, 13, 10, 27, 21, 18, 55, 43, 37, 34, 111, 87, 75, 69, 66, 223, 175, 151, 139, 133, 130, 447, 351, 303, 279, 267, 261, 258, 895, 703, 607, 559, 535, 523, 517, 514

Offset

1,1

Comments

Note that for each triangular array T(row+1,col) = 2 * T(row,col) +1 and that the change from T(row,col+1) to T(row,col) can be readily discerned. In the first array that pattern is 1 2 4 8 ...while in the second, it becomes 3 6 12 24 48 ... and in general, the pattern for the k-th array will begin with 2k-1.

Links

Table of n, a(n) for n=1..36.

Example

The first array begins
1
3 2
7 5 4
15 11 9 8
31 23 19 17 16
so a(1) begins with six. In general each triangular array will begin with
the next term from A079946.

Crossrefs

Sequence in context: A359091 A130012 A265740 * A106623 A115010 A244535

Adjacent sequences: A090321 A090322 A090323 * A090325 A090326 A090327

Keyword

easy,nonn,tabl

Author

Alford Arnold, Jan 26 2004

Status

approved