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 A000460 Eulerian numbers (Euler's triangle: column k=3 of A008292, column k=2 of A173018) (Formerly M4795 N2047) 15
 1, 11, 66, 302, 1191, 4293, 14608, 47840, 152637, 478271, 1479726, 4537314, 13824739, 41932745, 126781020, 382439924, 1151775897, 3464764515, 10414216090, 31284590870, 93941852511, 282010106381, 846416194536, 2540053889352, 7621839388981, 22869007827143 (list; graph; refs; listen; history; text; internal format)
 OFFSET 3,2 COMMENTS 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.) Number of permutations of [n] with exactly 2 descents. - Mike Zabrocki, Nov 10 2004 REFERENCES L. Comtet, "Permutations by Number of Rises; Eulerian Numbers." §6.5 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). LINKS Vincenzo Librandi, Table of n, a(n) for n = 3..1000 E. Banaian, S. Butler, C. Cox, J. Davis, J. Landgraf and S. Ponce A generalization of Eulerian numbers via rook placements, arXiv:1508.03673 [math.CO], 2015. L. Carlitz et al., Permutations and sequences with repetitions by number of increases, J. Combin. Theory, 1 (1966), 350-374. E. T. Frankel, A calculus of figurate numbers and finite differences, American Mathematical Monthly, 57 (1950), 14-25. [Annotated scanned copy] J. C. P. Miller, Letter to N. J. A. Sloane, Mar 26 1971 O. J. Munch, Om potensproduktsummer [Norwegian, English summary], Nordisk Matematisk Tidskrift, 7 (1959), 5-19. [Annotated scanned copy] O. J. Munch, Om potensproduktsummer [ Norwegian, English summary ], Nordisk Matematisk Tidskrift, 7 (1959), 5-19. Nagatomo Nakamura, Pseudo-Normal Random Number Generation via the Eulerian Numbers, Josai Mathematical Monographs, vol 8, p 85-95, 2015. P. A. Piza, Kummer numbers, Mathematics Magazine, 21 (1947/1948), 257-260. P. A. Piza, Kummer numbers, Mathematics Magazine, 21 (1947/1948), 257-260. [Annotated scanned copy] Simon Plouffe, Approximations de séries génératrices et quelques conjectures, Dissertation, Université du Québec à Montréal, 1992. Simon Plouffe, 1031 Generating Functions and Conjectures, Université du Québec à Montréal, 1992. J. Riordan, Review of Frankel (1950) [Annotated scanned copy] Eric Weisstein's World of Mathematics, Eulerian Number R. G. Wilson, V, Letter to N. J. A. Sloane, Apr. 1994 FORMULA a(n+2) = 3^(n+2) - (n+3)*2^(n+2) + (1/2)*(n+2)*(n+3). - Randall L. Rathbun (randallr(AT)abac.com), Jan 22 2002 G.f.: x^3*(1+x-4*x^2)/((1-x)^3*(1-2*x)^2*(1-3*x)). - Mike Zabrocki, Nov 10 2004 a(n) = 3^n - (n+1)*2^n + (1/2)*n*(n+1). [Gary Detlefs, Nov 11 2011] E.g.f.: exp(x)*(exp(2*x) - (1 + 2*x)*exp(x) + x + x^2/2). - Wolfdieter Lang, Apr 17 2017 MAPLE A000460:=-z*(-1-z+4*z**2)/(-1+3*z)/(2*z-1)**2/(z-1)**3; # Simon Plouffe in his 1992 dissertation MATHEMATICA k = 3; 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, 23}] (* or *) Array[3^(# + 2) - (# + 3)*2^(# + 2) + (1/2)*(# + 2)*(# + 3) &, 23] (* Michael De Vlieger, Aug 04 2015, after PARI *) PROG (PARI) A000460(n) = 3^(n+2)-(n+3)*2^(n+2)+(1/2)*(n+2)*(n+3) (MAGMA) [3^n-(n+1)*2^n+(1/2)*n*(n+1): n in [3..30]]; // Vincenzo Librandi, Apr 18 2017 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. A000295. Sequence in context: A325752 A221143 A022576 * A256583 A210392 A316110 Adjacent sequences:  A000457 A000458 A000459 * A000461 A000462 A000463 KEYWORD nonn,easy AUTHOR EXTENSIONS More terms from Christian G. Bower, May 12 2000 More terms from Mike Zabrocki, Nov 10 2004 STATUS approved

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Last modified October 16 15:31 EDT 2019. Contains 328101 sequences. (Running on oeis4.)