Search: id:A001517 Results 1-1 of 1 results found. %I A001517 M3062 N1240 %S A001517 1,3,19,193,2721,49171,1084483,28245729,848456353,28875761731, %T A001517 1098127402131,46150226651233,2124008553358849,106246577894593683, %U A001517 5739439214861417731,332993721039856822081,20651350143685984386753 %N A001517 Bessel polynomials y_n(x) (see A001498) evaluated at 2. %C A001517 Numerators of successive convergents to e using continued fraction 1+2/ (1+1/(6+1/(10+1/(14+1/(18+1/(22+1/26...)))))). %C A001517 Number of ways to use the elements of {1,..,k}, n<=k<=2n, once each to form a collection of n lists, each having length 1 or 2. - Bob Proctor, Apr 18 2005, Jun 26 2006 %D A001517 N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence). %D A001517 N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 (includes this sequence). %D A001517 L. Euler, 1737. %D A001517 J. W. L. Glaisher, Reports of British Assoc. Adv. Sci., 1871, pp. 16-18. %D A001517 I. S. Gradshteyn and I. M. Ryzhik, Tables of Integrals, Series and Products, 6th ed., Section 0.126, p. 2. %D A001517 D. H. Lehmer, Review of various tables by P. Pederson, Math. Comp., 2 (1946), 68-69. %D A001517 J. Riordan, Combinatorial Identities, Wiley, 1968, p. 77. %H A001517 T. D. Noe, Table of n, a(n) for n=0..100 %H A001517 INRIA Algorithms Project, Encyclopedia of Combinatorial Structures 131 %H A001517 Index entries for related partition-counting sequences %H A001517 Index entries for sequences related to Bessel functions or polynomials %F A001517 a(n) = Sum_{k=0..n} (n+k)!/(k!*(n-k)!) = (e/pi)^(1/2) K_{n+1/2}(1/2). %F A001517 a(n) = (4n-2)a(n-1) + a(n-2), n>=2. %F A001517 a(n) = (1/n!)*Sum_{k=0..n} (-1)^(n+k)*binomial(n,k)*A000522(n+k). - Vladeta Jovovic (vladeta(AT)eunet.rs), Sep 30 2006 %o A001517 (PARI) a(n)=sum(k=0,n,(n+k)!/k!/(n-k)!) %Y A001517 Essentially the same as A080893. %Y A001517 a(n) = A099022(n)/n!. %Y A001517 Partial sums: A105747. %Y A001517 Replace "lists" by "sets" in comment: A001515. %Y A001517 Cf. A001515, A001518, A002119, A053556, A053557. %Y A001517 Sequence in context: A119394 A101481 A155805 this_sequence A080893 A028854 A108292 %Y A001517 Adjacent sequences: A001514 A001515 A001516 this_sequence A001518 A001519 A001520 %K A001517 nonn,easy,nice %O A001517 0,2 %A A001517 N. J. A. Sloane (njas(AT)research.att.com). %E A001517 More terms from Vladeta Jovovic (vladeta(AT)eunet.rs), Apr 03 2000 %E A001517 Additional comments from Michael Somos, Jul 15, 2002. Search completed in 0.002 seconds