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.

A001243 Eulerian numbers (Euler's triangle: column k=7 of A008292, column k=6 of A173018).

Original entry on oeis.org

1, 247, 14608, 455192, 9738114, 162512286, 2275172004, 27971176092, 311387598411, 3207483178157, 31055652948388, 285997074307300, 2527925001876036, 21598596303099900, 179385804170146680
Offset: 7

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There are 2 versions of Euler's triangle:
* A008292 Classic version of Euler's triangle used by Comtet (1974).
* A173018 Version of Euler's triangle used by Graham, Knuth and Patashnik in Concrete Math. (1990).
Euler's triangle rows and columns indexing conventions:
* A008292 The rows and columns of the Eulerian triangle are both indexed starting from 1. (Classic version: used in the classic books by Riordan and Comtet.)
* A173018 The rows and columns of the Eulerian triangle are both indexed starting from 0. (Graham et al.)

References

  • L. Comtet, "Permutations by Number of Rises; Eulerian Numbers." ยง6.5 in Advanced Combinatorics: The Art of Finite and Infinite Expansions, rev. enl. ed. Dordrecht, Netherlands: Reidel, pp. 51 and 240-246, 1974.
  • L. Comtet, Advanced Combinatorics, Reidel, 1974, p. 243.
  • F. N. David and D. E. Barton, Combinatorial Chance. Hafner, NY, 1962, p. 151.
  • F. N. David, M. G. Kendall and D. E. Barton, Symmetric Function and Allied Tables, Cambridge, 1966, p. 260.
  • J. Riordan, An Introduction to Combinatorial Analysis, Wiley, 1958, p. 215.
  • 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

Cf. A008292 (classic version of Euler's triangle used by Comtet (1974).)
Cf. A173018 (version of Euler's triangle used by Graham, Knuth and Patashnik in Concrete Math. (1990).)
Cf. A000012, A000460, A000498, A000505, A000514 (columns for smaller k).

Programs

  • Magma
    [EulerianNumber(n,6): n in [7..40]]; // G. C. Greubel, Dec 30 2024
    
  • Mathematica
    k = 7; Table[k^(n + k - 1) + Sum[(-1)^i/i!*(k - i)^(n + k - 1) * Product[n + k + 1 - j, {j, 1, i}], {i, 1, k - 1}], {n, 1, 15}] (* Michael De Vlieger, Aug 04 2015, after PARI *)
  • PARI
    A001243(n)=7^(n+7-1)+sum(i=1,7-1,(-1)^i/i!*(7-i)^(n+7-1)*prod(j=1,i,n+7+1-j))
    
  • SageMath
    # from sage.all import * # (use for Python)
    from sage.combinat.combinat import eulerian_number
    print([eulerian_number(n,6) for n in range(7,41)]) # G. C. Greubel, Dec 30 2024

Formula

a(n) = 7^(n+7-1) + Sum_{i=1..7-1} ((-1)^i/i!)*(7-i)^(n+7-1) * Product_{j=1..i} (n+7+1 - j). - Randall L Rathbun, Jan 23 2002
For the general formula for the o.g.f. and e.g.f. see A123125. - Wolfdieter Lang, Apr 19 2017
a(n) = 7^(n+6) + Sum_{j=1..6} (-1)^j*binomial(n+7, j)*(7-j)^(n+6). - G. C. Greubel, Dec 30 2024

Extensions

More terms from Christian G. Bower, May 12 2000