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A001019 Powers of 9.
(Formerly M4653 N1992)
36
1, 9, 81, 729, 6561, 59049, 531441, 4782969, 43046721, 387420489, 3486784401, 31381059609, 282429536481, 2541865828329, 22876792454961, 205891132094649, 1853020188851841, 16677181699666569, 150094635296999121, 1350851717672992089 (list; graph; refs; listen; history; internal format)
OFFSET

0,2

COMMENTS

Same as Pisot sequences E(1,9), L(1,9), P(1,9), T(1,9). See A008776 for definitions of Pisot sequences.

Except for 1, the largest n-th power with n digits. - Amarnath Murthy (amarnath_murthy(AT)yahoo.com), Feb 09 2002

The 2002 comment by Amarnath Murthy should say more precisely "n-th power with *at most* n digits": a(22) has only 21 digits etc., a(44) has only 42 digits etc. [From Hagen von Eitzen (math(AT)von-eitzen.de), May 17 2009]

A000005(a(n)) = A005408(n+1). - Reinhard Zumkeller (reinhard.zumkeller(AT)gmail.com), Mar 04 2007

1/1 + 1/9 + 1/81 + ... = 9/8 [From Gary W. Adamson (qntmpkt(AT)yahoo.com), Aug 29 2008]

The compositions of n in which each natural number is colored by one of p different colors are called p-colored compositions of n. For n>=1, a(n) equals the number of 9-colored compositions of n such that no adjacent parts have the same color. - Milan Janjic, Nov 17 2011

REFERENCES

N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 (includes this sequence).

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

LINKS

T. D. Noe, Table of n, a(n) for n=0..100

P. J. Cameron, Sequences realized by oligomorphic permutation groups, J. Integ. Seqs. Vol. 3 (2000), #00.1.5.

INRIA Algorithms Project, Encyclopedia of Combinatorial Structures 274

Tanya Khovanova, Recursive Sequences

Y. Puri and T. Ward, Arithmetic and growth of periodic orbits, J. Integer Seqs., Vol. 4 (2001), #01.2.1.

Index entries for sequences related to linear recurrences with constant coefficients

FORMULA

a(n) = 9^n; a(n) = 9*a(n-1).

G.f.: 1/(1-9*x)

E.g.f.: exp(9*x)

MATHEMATICA

Table[9^n, {n, 0, 40}] (*From Vladimir Joseph Stephan Orlovsky, Feb 15 2011*)

CROSSREFS

Cf. A067470.

Sequence in context: A120997 A125630 A100062 * A074118 A050739 A158779

Adjacent sequences:  A001016 A001017 A001018 * A001020 A001021 A001022

KEYWORD

easy,nonn

AUTHOR

N. J. A. Sloane (njas(AT)research.att.com).

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Last modified February 13 08:12 EST 2012. Contains 205451 sequences.