A193739 Mirror of the triangle A193738.
1, 1, 1, 2, 2, 1, 3, 3, 2, 1, 4, 4, 3, 2, 1, 5, 5, 4, 3, 2, 1, 6, 6, 5, 4, 3, 2, 1, 7, 7, 6, 5, 4, 3, 2, 1, 8, 8, 7, 6, 5, 4, 3, 2, 1, 9, 9, 8, 7, 6, 5, 4, 3, 2, 1, 10, 10, 9, 8, 7, 6, 5, 4, 3, 2, 1, 11, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, 1, 12, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, 1, 13, 13, 12
Offset: 0
Examples
First six rows: 1 1....1 2....2....1 3....3....2....1 4....4....3....2...1 5....5....4....3...2...1
Links
- Reinhard Zumkeller, Rows n = 0..100 of triangle, flattened
- BBC, One man went to mow.
- Index entries for sequences related to songs
Crossrefs
Cf. A193738.
Programs
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Haskell
a193738 n k = a193738_tabl !! n !! k a193738_row n = a193738_tabl !! n a193738_tabl = map reverse a193739_tabl -- Reinhard Zumkeller, May 11 2013
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Mathematica
z = 12; p[0, x_] := 1 p[n_, x_] := x*p[n - 1, x] + 1; p[n_, 0] := p[n, x] /. x -> 0 q[n_, x_] := p[n, x] t[n_, k_] := Coefficient[p[n, x], x^(n - k)]; t[n_, n_] := p[n, x] /. x -> 0; w[n_, x_] := Sum[t[n, k]*q[n + 1 - k, x], {k, 0, n}]; w[-1, x_] := 1 g[n_] := CoefficientList[w[n, x], {x}] TableForm[Table[Reverse[g[n]], {n, -1, z}]] Flatten[Table[Reverse[g[n]], {n, -1, z}]] (* A193738 *) TableForm[Table[g[n], {n, -1, z}]] Flatten[Table[g[n], {n, -1, z}]] (* A193739 *)
Formula
Write w(n,k) for the triangle at A193738. The current triangle is then given by w(n,n-k).
Comments