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.

A203163 (n-1)-st elementary symmetric function of the first n terms of (1,2,3,4,1,2,3,4,1,2,3,4,...) = A010883.

Original entry on oeis.org

1, 3, 11, 50, 74, 172, 564, 2400, 2976, 6528, 20736, 86400, 100224, 214272, 670464, 2764800, 3096576, 6524928, 20238336, 82944000, 90906624, 189775872, 585252864, 2388787200, 2579890176, 5350883328, 16434855936, 66886041600
Offset: 1

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Author

Clark Kimberling, Dec 30 2011

Keywords

Examples

			Let esf abbreviate "elementary symmetric function". Then
0th esf of {1}:  1;
1st esf of {1,2}:  1+2 = 3;
2nd esf of {1,2,3} is 1*2 + 1*3 + 2*3 = 11.
		

Crossrefs

Programs

  • Mathematica
    f[k_] := 1 + Mod[k + 3, 4]; t[n_] := Table[f[k], {k, 1, n}]
    a[n_] := SymmetricPolynomial[n - 1, t[n]]
    Table[a[n], {n, 1, 33}]  (* A203163 *)
    LinearRecurrence[{0,0,0,48,0,0,0,-576},{1,3,11,50,74,172,564,2400},50] (* Harvey P. Dale, Aug 18 2020 *)
  • PARI
    Vec(x*(36*x^6+28*x^5+26*x^4+50*x^3+11*x^2+3*x+1)/(24*x^4-1)^2 + O(x^100)) \\ Colin Barker, Aug 15 2014

Formula

G.f.: x*(36*x^6 + 28*x^5 + 26*x^4 + 50*x^3 + 11*x^2 + 3*x + 1) / (24*x^4 - 1)^2. - Colin Barker, Aug 15 2014