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.

A057537 Number of ways of making change for n Euro-cents using the Euro currency.

Original entry on oeis.org

1, 1, 2, 2, 3, 4, 5, 6, 7, 8, 11, 12, 15, 16, 19, 22, 25, 28, 31, 34, 41, 44, 51, 54, 61, 68, 75, 82, 89, 96, 109, 116, 129, 136, 149, 162, 175, 188, 201, 214, 236, 249, 271, 284, 306, 328, 350, 372, 394, 416, 451, 473, 508, 530, 565, 600, 635, 670, 705, 740, 793, 828
Offset: 0

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Author

Thomas Brendan Murphy (murphybt(AT)tcd.ie), Sep 06 2000

Keywords

Comments

Euro currency has coins and bills of size 1, 2, 5, 10, 20, 50, 100, 200, 500, 1000, 2000, 5000, 10000, 20000, 50000 cents.
Differs from A001313 first at n=100. - Georg Fischer, Oct 06 2018

References

  • R. L. Graham, D. E. Knuth and O. Patashnik, Concrete Mathematics. Addison-Wesley, Reading, MA, 1990, p. 316.
  • G. Pólya and G. Szegő, Problems and Theorems in Analysis, Springer-Verlag, NY, 2 vols., 1972, Vol. 1, p. 1.

Crossrefs

Cf. A001313.

Programs

  • Maple
    gf:= 1/expand((1-x) * (1-x^2) * (1-x^5) * (1-x^10) * (1-x^20) * (1-x^50) * (1-x^100) * (1-x^200) * (1-x^500) * (1-x^1000) * (1-x^2000) * (1-x^5000) * (1-x^10000) * (1-x^20000) * (1-x^50000)):
    a:= n-> coeff(series(gf, x, n+1), x, n):
    seq(a(n), n=0..100);
  • Mathematica
    f = 1/Times@@(1 - x^{1, 2, 5, 10, 20, 50, 100, 200, 500, 1000, 2000, 5000, 10000, 20000, 50000}); a[n_] := SeriesCoefficient[f, {x, 0, n}]; Table[a[n], {n, 1, 61}] (* Jean-François Alcover, Nov 28 2013, after Maple *)
  • PARI
    coins(v[..])=my(x='x); prod(i=1,#v,1/(1-x^v[i]))
    Vec(coins(1, 2, 5, 10, 20, 50, 100, 200)+O(x^99)) \\ Charles R Greathouse IV, Jan 24 2022

Formula

G.f.: 1/((1-x) * (1-x^2) * (1-x^5) * (1-x^10) * (1-x^20) * (1-x^50) * (1-x^100) * (1-x^200) * (1-x^500) * (1-x^1000) * (1-x^2000) * (1-x^5000) * (1-x^10000) * (1-x^20000) * (1-x^50000)).