

A000007


The characteristic function of 0: a(n) = 0^n.
(Formerly M0002)


421



1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
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OFFSET

0,1


COMMENTS

Changing the offset to 1 gives the arithmetical function a(1) = 1, a(n) = 0 for n > 1, the identity function for Dirichlet multiplication (see Apostol).  N. J. A. Sloane
Hankel transform (see A001906 for definition) of : A000007 (powers of 0), A000012 (powers of 1), A000079 (powers of 2), A000244 (powers of 3), A000302 (powers of 4), A000351 (powers of 5), A000400 (powers of 6), A000420 (powers of 7), A001018 (powers of 8), A001019 (powers of 9), A011557 (powers of 10), A001020 (powers of 11), etc. ...  Philippe Deléham, Jul 07 2005
This is the identity sequence with respect to convolution.  David W. Wilson, Oct 30 2006
a(A000004(n)) = 1; a(A000027(n)) = 0.  Reinhard Zumkeller, Oct 12 2008
The alternating sum of the nth row of Pascal's triangle gives the characteristic function of 0, a(n) = 0^n.  Daniel Forgues, May 25 2010
The number of maximal selfavoiding walks from the NW to SW corners of a 1 X n grid.  Sean A. Irvine, Nov 19 2010
Historically there has been some disagreement as to whether 0^0 = 1. Graphing x^0 seems to support that conclusion, but graphing 0^x instead suggests that 0^0 = 0. Euler and Knuth have argued in favor of 0^0 = 1. For some calculators, 0^0 triggers an error, while in Mathematica, 0^0 is Indeterminate.  Alonso del Arte, Nov 15 2011
Another consequence of changing the offset to 1 is that then this sequence can be described as the sum of Moebius mu(d) for the divisors d of n.  Alonso del Arte, Nov 28 2011
With the convention 0^0 = 1, 0^n = 0 for n > 0, the sequence a(n) = 0^nk, which equals 1 when n = k and is 0 for n >= 0, has g.f. x^k. A000007 is the case k = 0.  George F. Johnson, Mar 08 2013


REFERENCES

T. M. Apostol, Introduction to Analytic Number Theory, SpringerVerlag, 1976, page 30.
N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).


LINKS

David Wasserman, Table of n, a(n) for n = 0..1000
Paul Barry, A Catalan Transform and Related Transformations on Integer Sequences, Journal of Integer Sequences, Vol. 8 (2005), Article 05.4.5.
Paul Barry, A Note on a Family of Generalized Pascal Matrices Defined by Riordan Arrays, Journal of Integer Sequences, 16 (2013), #13.5.4.
Dr. Math, 0^0 (zero to the zero power)
Daniele A. Gewurz and Francesca Merola, Sequences realized as Parker vectors of oligomorphic permutation groups, J. Integer Seqs., Vol. 6, 2003.
Donald E. Knuth, Two notes on notation. See page 6 on 0^0.
Index entries for "core" sequences
Index entries for characteristic functions


FORMULA

Multiplicative with a(p^e) = 0.  David W. Wilson, Sep 01 2001
a(n) = floor(1/(n + 1)).  Franz Vrabec, Aug 24 2005
a(n) = ((n + 1)!^2 mod (n + 2))*((n + 2)!^2 mod (n + 3)), with n >= 0.  Paolo P. Lava, Apr 24 2007
a(n) = 1  {[(n + 1)! + 1] mod (n + 1)}, with n >= 0.  Paolo P. Lava, May 22 2007
a(n) = 1  [(n + 2) mod (n + 1)], with n >= 0.  Paolo P. Lava, Jun 27 2007
a(n) = C(2*n, n) mod 2.  Paolo P. Lava, Aug 31 2007
a(n) = ((1)^A000040(n) + 1)/2.  JuriStepan Gerasimov, Oct 25 2009
As a function of Bernoulli numbers, (Cf. A027641: (1, 1/2, 1/6, 0, 1/30, ...)); triangle A074909 (the beheaded Pascal's triangle) * B_n as a vector = [1, 0, 0, 0, 0,...].  Gary W. Adamson, Mar 05 2012
a(n) = Sum_{k = 0..n} exp(2*Pi*i*k/(n+1)) is the sum of the (n+1)th roots of unity.  Franz Vrabec, Nov 09 2012


EXAMPLE

a(4) = 0 = (1, 5, 10, 10, 5) dot (1, 1/2, 1/6 0, 1/30) = (1  5/2 + 5/3 + 0  1/6) = 0; where (1, 5, 10, 10, 5) = row 4 of triangle A074909.  Gary W. Adamson, Mar 05 2012


MAPLE

A000007 := proc(n) if n = 0 then 1 else 0; fi; end;
with(combstruct); spec := [A, {A=Z} ]; [seq(combstruct[count](spec, size=n), n=1..20)];


MATHEMATICA

Table[If[n == 0, 1, 0], {n, 0, 99}]
Table[Boole[n == 0], {n, 0, 99}] (* Michael Somos, Aug 25 2012 *)
LinearRecurrence[{#1  2, #1  1}, {1, 0}, 105] (* Robert G. Wilson v, Jun 15 2013 *)


PROG

(PARI) {a(n) = !n};
(MAGMA) [1] cat [0:n in [1..100]]; // Sergei Haller, Dec 21 2006
(Haskell)
a000007 = (0 ^)
a000007_list = 1 : repeat 0
 Reinhard Zumkeller, May 07 2012, Mar 27 2012


CROSSREFS

Characteristic function of g: this sequence (g = 0), A063524 (g = 1), A185012 (g = 2), A185013 (g = 3), A185014 (g = 4), A185015 (g = 5), A185016 (g = 6), A185017 (g = 7).  Jason Kimberley, Oct 14 2011
Characteristic function of multiples of g: this sequence (g = 0), A000012 (g = 1), A059841 (g = 2), A079978 (g = 3), A121262 (g = 4), A079998 (g = 5), A079979 (g = 6), A082784 (g = 7).  Jason Kimberley, Oct 14 2011
Cf. A074909, A027641.
Sequence in context: A185013 A185012 A185017 * A014041 A015868 A015824
Adjacent sequences: A000004 A000005 A000006 * A000008 A000009 A000010


KEYWORD

core,easy,nonn,mult


AUTHOR

N. J. A. Sloane


STATUS

approved



