This site is supported by donations to The OEIS Foundation.

 Annual appeal: Please make a donation to keep the OEIS running! Over 6000 articles have referenced us, often saying "we discovered this result with the help of the OEIS". Other ways to donate

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A052549 a(0)=1; a(n) = 5*2^(n-1) - 1, n>0. 7
 1, 4, 9, 19, 39, 79, 159, 319, 639, 1279, 2559, 5119, 10239, 20479, 40959, 81919, 163839, 327679, 655359, 1310719, 2621439, 5242879, 10485759, 20971519, 41943039, 83886079, 167772159, 335544319, 671088639, 1342177279, 2684354559 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,2 COMMENTS A153894 is a better version of this sequence. - N. J. A. Sloane, Feb 07 2009 Equals binomial transform of [1, 3, 2, 3, 2, 3, 2,...] and row sums of triangle A140183. - Gary W. Adamson, May 11 2008 LINKS INRIA Algorithms Project, Encyclopedia of Combinatorial Structures 486 Index entries for linear recurrences with constant coefficients, signature (3,-2). FORMULA G.f.: -(-x+x^2-1)/((-1+2*x)*(-1+x)). -2*a(n) + a(n+1) - 1 = 0, n>0. Row sums of triangle A133601. - Gary W. Adamson, Sep 18 2007 MAPLE spec := [S, {S=Prod(Sequence(Union(Z, Z)), Union(Z, Sequence(Z)))}, unlabeled]: seq(combstruct[count](spec, size=n), n=0..20); MATHEMATICA a=4; lst={1, a}; k=5; Do[a+=k; AppendTo[lst, a]; k+=k, {n, 0, 5!}]; lst (* Vladimir Joseph Stephan Orlovsky, Dec 15 2008 *) CROSSREFS Cf. A133601, A140183, A153894. Sequence in context: A008135 A009885 * A153894 A214318 A034479 A183304 Adjacent sequences:  A052546 A052547 A052548 * A052550 A052551 A052552 KEYWORD easy,nonn AUTHOR encyclopedia(AT)pommard.inria.fr, Jan 25 2000 EXTENSIONS More terms from James A. Sellers, Jun 06 2000 STATUS approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent | More pages
The OEIS Community | Maintained by The OEIS Foundation Inc.