Search: id:A053556 Results 1-1 of 1 results found. %I A053556 %S A053556 1,1,2,3,8,30,144,280,5760,45360,44800,3991680,43545600,172972800, %T A053556 6706022400,93405312000,42268262400,22230464256000,376610217984000, %U A053556 250298560512000,11640679464960000,196503623737344000,17841281393295360000 %N A053556 Denominator of Sum_{k=0..n} (-1)^k/k!. %C A053556 Denominator of probability of a derangement of n things (A000166(n)/n!). %C A053556 Also numerators of successive convergents to e using continued fraction 2+1/(1+1/(2+2/(3+3/(4+4/(5+5/(6+6/(7+7/8+...))))))). %D A053556 L. Lorentzen and H. Waadeland, Continued Fractions with Applications, North-Holland 1992, p. 562. %D A053556 E. Maor, e: The Story of a Number, Princeton Univ. Press 1994, pp. 151 and 157. %H A053556 T. D. Noe, Table of n, a(n) for n=0..100 %H A053556 Leonhardo Eulero, Introductio in analysin infinitorum. Tomus primus, Lausanne, 1748. %H A053556 L. Euler, Introduction a l'analyse infinitesimal Tome premier, Tome second, trad. du latin en francais par J. B. Labey, Paris, 1796-1797. %H A053556 %H A053556 Eric Weisstein's World of Mathematics, Subfactorial [From Eric W. Weisstein (eric(AT)weisstein.com), Sep 12 2008] %F A053556 Let -e^(-x)/(x-1)= Sum(n, 0, infty)a_n/b_n *x^n . Then sequence b_n is A053556 - Aleksandar Petojevic (apetoje(AT)ptt.yu), Apr 14 2004 %e A053556 1, 0, 1/2, 1/3, 3/8, 11/30, 53/144, 103/280, 2119/5760, ... %t A053556 Table[ Denominator[ Sum[ -(-1)^k/k!, {k, 0, n}]], {n, 0, 20}] (from Robert G. Wilson v (rgwv(at)rgwv.com), Oct 13 2005) %Y A053556 Cf. A053557 (numerators), A053518-A053520. See also A103816. %Y A053556 a(n) = (D(n, n) of A103360), A053557/A053556 = A000166/n! = (N(n, n) of A103361)/(D(n, n) of A103360), Cf. A053518-A053520. %Y A053556 Sequence in context: A012886 A078918 A054104 this_sequence A001048 A141520 A072042 %Y A053556 Adjacent sequences: A053553 A053554 A053555 this_sequence A053557 A053558 A053559 %K A053556 nonn,frac,nice,easy %O A053556 0,3 %A A053556 N. J. A. Sloane (njas(AT)research.att.com), Jan 17 2000 %E A053556 More terms from Vladeta Jovovic (vladeta(AT)eunet.rs), Mar 31 2000 Search completed in 0.001 seconds