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.

A193092 Augmentation of the triangular array P given by p(n,k)=k! for 0<=k<=n. See Comments.

Original entry on oeis.org

1, 1, 1, 1, 2, 3, 1, 3, 7, 13, 1, 4, 12, 32, 69, 1, 5, 18, 58, 173, 421, 1, 6, 25, 92, 321, 1058, 2867, 1, 7, 33, 135, 523, 1977, 7159, 21477, 1, 8, 42, 188, 790, 3256, 13344, 53008, 175769, 1, 9, 52, 252, 1134, 4986, 21996, 97956, 427401, 1567273
Offset: 0

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Author

Clark Kimberling, Jul 30 2011

Keywords

Comments

For an introduction to the unary operation "augmentation" as applied to triangular arrays or sequences of polynomials, see A193091.
Regarding W=A193092, we have w(n,n)=A088368.

Examples

			First 7 rows:
1
1...1
1...2....3
1...3....7.....13
1...4....12....32....69
1...5....18....58....173...421
1...6....25....92....321...1058...2867
The matrix method described at A193091 shows that row 3 arises from row 2 as the matrix product
............. (1...1...2...4)
(1...2...3) * (0...1...1...2) = (1...3...7...13)
............. (0...0...1...1).
The equivalent polynomial substitution method:
x^2+2x+3 -> (x^3+x^2+2x+4)+2(x^2+x+2)+3(x+1)= x^3+3x^2+7x+13.
		

Crossrefs

Programs

  • Mathematica
    p[n_, k_] := k!
    Table[p[n, k], {n, 0, 5}, {k, 0, n}]
    m[n_] := Table[If[i <= j, p[n + 1 - i, j - i], 0], {i, n}, {j, n + 1}]
    TableForm[m[4]]
    w[0, 0] = 1; w[1, 0] = p[1, 0]; w[1, 1] = p[1, 1];
    v[0] = w[0, 0]; v[1] = {w[1, 0], w[1, 1]};
    v[n_] := v[n - 1].m[n]
    TableForm[Table[v[n], {n, 0, 6}]] (* A193092 *)
    Flatten[Table[v[n], {n, 0, 8}]]