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A133332 Olinde Rodrigues recursive polynomial for Inversions of permutations: U(n,x)=Product[Sun[x^i,{i,0,m-1}],{m,0,n}]. 0
1, 1, 1, 3, 3, 1, 1, 4, 10, 16, 19, 16, 10, 4, 1, 1, 5, 15, 35, 65, 101, 135, 155, 155, 135, 101, 65, 35, 15, 5, 1, 1, 6, 21, 56, 126, 246, 426, 666, 951, 1246, 1506, 1686, 1751, 1686, 1506, 1246, 951, 666, 426, 246, 126, 56, 21, 6, 1, 1, 7, 28, 84, 210, 462, 917 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,4

COMMENTS

The polynomial powers grow as : I(n)=n!binomial[n,2]/2

REFERENCES

Warren P. Johnson,American Math. Monthly,Oct 2007,volume 114, number 8, pages 752-758

LINKS

Table of n, a(n) for n=1..63.

FORMULA

U(n,x)=Product[Sun[x^i,{i,0,m-1}],{m,0,n}] a(n,m)=CoeffiecientList[U[n,x),x]

EXAMPLE

{1},

{1},

{1, 3, 3, 1},

{1, 4, 10, 16, 19, 16, 10, 4, 1},

{1, 5, 15, 35, 65, 101, 135, 155, 155, 135, 101, 65, 35, 15, 5, 1},

{1, 6, 21, 56, 126, 246, 426, 666, 951, 1246, 1506, 1686, 1751, 1686, 1506,1246, 951, 666, 426, 246, 126, 56, 21, 6, 1},

MATHEMATICA

f[q_, n_] = If[n == 0, 1, Sum[q^i, {i, 0, n - 1}]]; g[q_, n_] = Product[f[q, n], {m, 0, n}]; a = Table[CoefficientList[g[x, n], x], {n, 0, 10}]

CROSSREFS

Sequence in context: A109439 A133333 A171876 * A179680 A123562 A046218

Adjacent sequences:  A133329 A133330 A133331 * A133333 A133334 A133335

KEYWORD

nonn,uned

AUTHOR

Roger L. Bagula, Oct 19 2007

STATUS

approved

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Last modified May 23 08:43 EDT 2013. Contains 225585 sequences.