login
This site is supported by donations to The OEIS Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A134527 G.f. A(x) satisfies: A(x) = Sum_{n>=0} [x*A(x)]^(2^n-1). 0
1, 1, 1, 2, 5, 11, 24, 58, 149, 385, 1001, 2652, 7140, 19384, 52944, 145590, 402949, 1121117, 3133255, 8793372, 24774557, 70045871, 198672464, 565144064, 1611946284, 4609140916, 13209415116, 37937455636, 109171460104, 314736939884, 908930799572, 2629120466966 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,4

COMMENTS

Apparently: Number of Dyck n-paths with all ascent lengths being 1 less than a power of 2. [David Scambler, May 07 2012]

LINKS

Table of n, a(n) for n=0..31.

FORMULA

G.f.: A(x) = Series_Reversion{x/[Sum_{n>=0} x^(2^n-1)]}.

MATHEMATICA

f[x_, y_, d_] := f[x, y, d] = If[x < 0 || y < x, 0, If[x == 0 && y == 0, 1, f[x - 1, y, 0] + f[x, y - If[d == 0, 1, 2*d], If[d == 0, 1, 2*d]]]]; Table[f[n, n, 0], {n, 0, 28}] (* David Scambler, May 07 2012 *)

PROG

(PARI) a(n)=polcoeff(serreverse(x/sum(j=0, #binary(n), x^(2^j-1)+ x*O(x^n))), n)

CROSSREFS

Sequence in context: A018007 A071879 A228862 * A124379 A084978 A118036

Adjacent sequences:  A134524 A134525 A134526 * A134528 A134529 A134530

KEYWORD

nonn

AUTHOR

Paul D. Hanna, Nov 19 2007

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.

License Agreements, Terms of Use, Privacy Policy .

Last modified June 24 15:07 EDT 2017. Contains 288697 sequences.