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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.

A301420 Sums of positive coefficients in generalized Chebyshev polynomials of the first kind, for a family of 5 data.

Original entry on oeis.org

1, 5, 31, 205, 1376, 9251, 62210, 418361, 2813485, 18920751, 127242501, 855708865, 5754662616, 38700243965, 260260067876, 1750255192001, 11770508100345, 79156948982921, 532332378421395, 3579947998967501, 24075236064574376
Offset: 1

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Author

Gregory Gerard Wojnar, Mar 20 2018

Keywords

Comments

Re-express the Girard-Waring formulae to yield the mean powers in terms of the mean symmetric polynomials in the data values. Then for a family of 5 data, the sum of the positive coefficients in these polynomials is a(n). a(n+1)/a(n) approaches 1/(2^(1/5)-1). (For a family of 2 data, the coefficients of these polynomials give the Chebyshev polynomials of the first kind.) See extended comment in A301417.

Crossrefs

Programs

Formula

G.f.: (-x*(x+1)^4+1)/(x^6+4*x^5+5*x^4-5*x^2-6*x+1); this denominator equals (1-x)*(2-(x+1)^5) (conjectured).
a(n+14) = 7*a(n+13) - a(n+12) - 6*a(n+11) + 2*a(n+10) - a(n+9) + 4*a(n+8) + a(n+7) + 4*a(n+5) + 2*a(n+4) - a(n+3) - 5*a(n+2) - 4*a(n+1) - a(n) (conjectured).