cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A103219 Triangle read by rows: T(n,k) = (n+1-k)*(4*(n+1-k)^2 - 1)/3+2*k*(n+1-k)^2.

Original entry on oeis.org

1, 10, 3, 35, 18, 5, 84, 53, 26, 7, 165, 116, 71, 34, 9, 286, 215, 148, 89, 42, 11, 455, 358, 265, 180, 107, 50, 13, 680, 553, 430, 315, 212, 125, 58, 15, 969, 808, 651, 502, 365, 244, 143, 66, 17, 1330, 1131, 936, 749, 574, 415, 276, 161, 74, 19, 1771, 1530, 1293
Offset: 0

Views

Author

Lambert Klasen (lambert.klasen(AT)gmx.de) and Gary W. Adamson, Jan 26 2005

Keywords

Comments

The triangle is generated from the product B * A of the infinite lower triangular matrices A =
1 0 0 0...
3 1 0 0...
5 3 1 0...
7 5 3 1...
...
and B =
1 0 0 0...
1 3 0 0...
1 3 5 0...
1 3 5 7...
...

Examples

			Triangle begins:
1,
10,3,
35,18,5,
84,53,26,7,
165,116,71,34,9,
286,215,148,89,42,11,
		

Crossrefs

Row sums give A103220.
T(n, 0) = (n+1)*(4*(n+1)^2 - 1)/3 = A000447(n+1);
T(n+1, n)= 8*n+2 = A017089(n+1);
Cf. A103218 (for product A*B), A103220.

Programs

  • Mathematica
    T[n_, k_] := (n + 1 - k)*(4*(n + 1 - k)^2 - 1)/3 + 2*k*(n + 1 - k)^2; Flatten[ Table[ T[n, k], {n, 0, 10}, {k, 0, n}]] (* Robert G. Wilson v, Feb 10 2005 *)
  • PARI
    T(n,k)=(n+1-k)*(4*(n+1-k)^2-1)/3+2*k*(n+1-k)^2; for(i=0,10, for(j=0,i,print1(T(i,j),","));print())