A002179 Numerators of Cotesian numbers (not in lowest terms): A002176*C(n,2).

0, 1, 3, 12, 50, 27, 1323, -928, 1080, -48525, -3237113, -7587864, -31268252574, -770720657, -232936065, -179731134720, -542023437008852, -3212744374395, -926840515700222955, -389358194177500, -17858352159793110

Offset: 2

Author

N. J. A. Sloane

Keywords

• sign
• easy

References

• W. W. Johnson, On Cotesian numbers: their history, computation and values to n=20, Quart. J. Pure Appl. Math., 46 (1914), 52-65.
• N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 (includes this sequence).
• N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).

Links

• W. M. Johnson, On Cotesian numbers: their history, computation and values to n=20, Quart. J. Pure Appl. Math., 46 (1914), 52-65. [Annotated scanned copy]

Crossrefs

Cf. A100640/A100641, A100620/A100621, A002176, A002177, A002178.

Programs

Mathematica

cn[n_, 0] := Sum[n^j*StirlingS1[n, j]/(j+1), {j, 1, n+1}]/n!; cn[n_, n_] := cn[n, 0]; cn[n_, k_] := 1/n!*Binomial[n, k]*Sum[n^(j+m)*StirlingS1[k, j]*StirlingS1[n-k, m]/((m+1)*Binomial[j+m+1, m+1]), {m, 1, n}, {j, 1, k+1}]; A002176[n_] := LCM @@ Table[Denominator[cn[n, k]], {k, 0, n}]; a[2] = 0; a[n_] := A002176[n-1]*cn[n-1, 2]; Table[a[n], {n, 2, 22}] (* Jean-François Alcover, Oct 08 2013 *)

PARI

cn(n)= mattranspose(matinverseimage( matrix(n+1,n+1,k,m,(m-1)^(k-1)),matrix(n+1,1,k,m,n^(k-1)/k)))[ 1, ] \\ vector of quadrature formula coefficients via matrix solution

PARI

ncn(n)= denominator(cn(n))*cn(n); nk(n,k)= if(k<0 || k>n,0,ncn(n)[ k+1 ]); A002177(n)= nk(n,2)

Extensions

More terms from Michael Somos