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.

A287314 Triangle read by rows, the coefficients of the polynomials generating the columns of A287316.

Original entry on oeis.org

1, 0, 1, 0, -1, 2, 0, 4, -9, 6, 0, -33, 82, -72, 24, 0, 456, -1225, 1250, -600, 120, 0, -9460, 27041, -30600, 17700, -5400, 720, 0, 274800, -826336, 1011017, -661500, 249900, -52920, 5040, 0, -10643745, 33391954, -43471624, 31149496, -13524000, 3622080, -564480, 40320
Offset: 0

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Author

Peter Luschny, May 27 2017

Keywords

Comments

The zeta polynomials for the poset P_n of ordered pairs (S,T) where S,T are subsets of [n] with |S| = |T| ordered component-wise by inclusion. - Geoffrey Critzer, Jan 22 2021

Examples

			Triangle starts:
[0] 1
[1] 0,      1
[2] 0,     -1,       2
[3] 0,      4,      -9,       6
[4] 0,    -33,      82,     -72,      24
[5] 0,    456,   -1225,    1250,    -600,    120
[6] 0,  -9460,   27041,  -30600,   17700,  -5400,    720
[7] 0, 274800, -826336, 1011017, -661500, 249900, -52920, 5040
...
For example let p4(x) = -33*x + 82*x^2 - 72*x^3 + 24*x^4 then p4(n) = A169712(n).
		

Crossrefs

Cf. A287316, A000384 (p2), A169711 (p3), A169712 (p4), A169713 (p5).
Cf. A000275(n), A212855.

Programs

  • Maple
    A287314_row := proc(n) local k; sum(z^k/k!^2, k = 0..infinity);
    series(%^x, z=0, n+1): n!^2*coeff(%,z,n); seq(coeff(%,x,k), k=0..n) end:
    for n from 0 to 8 do print(A287314_row(n)) od;
    A287314_poly := proc(n) local k, x; sum(z^k/k!^2, k = 0..infinity);
    series(%^x, z=0, n+1): unapply(n!^2*coeff(%, z, n), x) end:
    for n from 0 to 7 do A287314_poly(n) od;
  • Mathematica
    nn = 10; e[x_] := Sum[x^n/n!^2, {n, 0, nn}];
    f[list_] := CoefficientList[InterpolatingPolynomial[Table[{i, list[[i]]}, {i, 1, nn}], m], m];Drop[Map[f,Transpose[Table[Table[n!^2, {n, 0, nn}] CoefficientList[
    Series[e[x]^k, {x, 0, nn}], x], {k, 1, nn}]]], -1] // Grid (* Geoffrey Critzer, Jan 22 2021 *)

Formula

Sum_{k=0..n} abs(T(n,k)) = A000275(n) = A212855_row(2).