[go: up one dir, main page]

login
A146023
Triangle read by rows, square of A027293.
4
1, 2, 1, 5, 2, 1, 10, 5, 2, 1, 20, 10, 5, 2, 1, 36, 20, 10, 5, 2, 1, 65, 36, 20, 10, 5, 2, 1, 110, 65, 36, 20, 10, 5, 2, 1, 185, 110, 65, 36, 20, 10, 5, 2, 1, 300, 185, 110, 65, 36, 20, 10, 5, 2, 1
OFFSET
0,2
COMMENTS
Triangle, A000712 (1, 2, 5, 10, 20, 36,...) in every column.
Row sums = A000713: (1, 3, 8, 18, 38, 74, 139,...)
Note that we are working here in the world of lower triangular matrices. - N. J. A. Sloane, Jun 15 2020
LINKS
Robert Price, Table of n, a(n) for n = 0..819 (first 40 rows)
EXAMPLE
First few rows of the triangle =
1;
2, 1;
5, 2, 1;
10, 5, 2, 1;
20, 10, 5, 2, 1;
36, 20, 10, 5, 2, 1;
65, 36, 20, 10, 5, 2, 1;
110, 65, 36, 20, 10, 5, 2, 1;
...
MATHEMATICA
lim = 10;
A000712 = Table [Length@IntegerPartitions[n, All, Range@n~Join~Range@n], {n, 0, lim - 1}]
Table[Reverse[Take[A000712, n]], {n, lim}] // Flatten (* Robert Price, Jun 15 2020 *)
CROSSREFS
KEYWORD
nonn,tabl
AUTHOR
Gary W. Adamson, Oct 26 2008
EXTENSIONS
Extraneous data deleted by Robert Price, Jun 15 2020
STATUS
approved