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

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A006155 Expansion of 1/(2-x-e^x).
(Formerly M1945)
1
1, 2, 9, 61, 551, 6221, 84285, 1332255, 24066691, 489100297, 11044268633, 274327080611, 7433424980943, 218208342366093, 6898241919264181, 233651576126946103, 8441657595745501019, 324052733365292875025 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

REFERENCES

Getu, S.; Shapiro, L. W.; Combinatorial view of the composition of functions. Ars Combin. 10 (1980), 131-145.

N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).

LINKS

Table of n, a(n) for n=0..17.

INRIA Algorithms Project, Encyclopedia of Combinatorial Structures 157

FORMULA

E.g.f.: 1/(2-x-exp(x)).

MATHEMATICA

With[{nn=20}, CoefficientList[Series[1/(2-x-E^x), {x, 0, nn}], x] Range[0, nn]!] (* Harvey P. Dale, Apr 27 2018 *)

CROSSREFS

Cf. A032112.

Sequence in context: A192939 A107883 A088182 * A121870 A268450 A146887

Adjacent sequences:  A006152 A006153 A006154 * A006156 A006157 A006158

KEYWORD

nonn,easy

AUTHOR

Simon Plouffe

EXTENSIONS

More terms from Ralf Stephan, Mar 12 2004

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 August 18 00:28 EDT 2018. Contains 313817 sequences. (Running on oeis4.)