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.

A001238 Differences of reciprocals of unity.

Original entry on oeis.org

63, 22631, 30480800, 117550462624, 1083688832185344, 21006340945438768128, 778101042571221893382144, 51150996584622542869024997376, 5626686079269855254796985958400000, 987233834003503822099304377378406400000
Offset: 1

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Keywords

References

  • F. N. David, M. G. Kendall and D. E. Barton, Symmetric Function and Allied Tables, Cambridge, 1966, p. 228.
  • 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).

Crossrefs

Column 5 in triangle A008969.

Programs

  • Mathematica
    a[n_] := -(Factorial[n + 1]^5)*Sum[(-1)^k Binomial[n + 1, k]/k^5, {k, 1, n + 1}];Table[a[n],{n,10}] (* James C. McMahon, Dec 12 2023 *)
  • PARI
    a(n) = (n+1)!^5 * sum(k=1, n+1, (-1)^(k+1)*binomial(n+1,k)/k^5); \\ Michel Marcus, Apr 28 2020

Formula

a(n) = (n+1)!^5 * Sum_{k=1..n+1} ((-1)^(k+1)*C(n+1,k)/k^5). - Sean A. Irvine, Mar 30 2012; corrected by Michel Marcus, Apr 28 2020

Extensions

More terms from Sean A. Irvine, Mar 29 2012