A237587 Triangle read by rows in which row n lists the first n odd squares in decreasing order.

1, 9, 1, 25, 9, 1, 49, 25, 9, 1, 81, 49, 25, 9, 1, 121, 81, 49, 25, 9, 1, 169, 121, 81, 49, 25, 9, 1, 225, 169, 121, 81, 49, 25, 9, 1, 289, 225, 169, 121, 81, 49, 25, 9, 1, 361, 289, 225, 169, 121, 81, 49, 25, 9, 1, 441, 361, 289, 225, 169, 121, 81, 49, 25, 9, 1

Offset

1,2

Comments

The sum of row n gives A000447(n).

The alternatig sum of row n gives A077221(n).

Links

Table of n, a(n) for n=1..66.

Formula

T(n,k) = (2*(n-k+1)-1)^2, n >=1, 1<=k<=n.

Example

Triangle begins:
1;
9,     1;
25,    9,   1;
49,   25,   9,   1;
81,   49,  25,   9,   1;
121,  81,  49,  25,   9,   1;
169, 121,  81,  49,  25,   9,   1;
225, 169, 121,  81,  49,  25,   9,   1;
289, 225, 169, 121,  81,  49,  25,   9,   1;
361, 289, 225, 169, 121,  81,  49,  25,   9,   1;
...

Crossrefs

Cf. A000290, A000447, A016754, A055461, A077221.

Sequence in context: A317051 A013616 A205381 * A328621 A191871 A181318

Adjacent sequences: A237584 A237585 A237586 * A237588 A237589 A237590

Keyword

nonn,tabl

Author

Omar E. Pol, Feb 16 2014

Status

approved