

A259346


If n = 2^k then a(n) = 3^k, otherwise a(n) = 0.


2



1, 3, 0, 9, 0, 0, 0, 27, 0, 0, 0, 0, 0, 0, 0, 81, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 243, 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, 729, 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

1,2


LINKS

Amiram Eldar, Table of n, a(n) for n = 1..10000
Lakhtakia, Akhlesh and Russell Messier, Selfsimilar sequences and chaos from Gauss sums, Computers & Graphics, Vol. 13, No. 1 (1989), pp. 5962. See Eq. (4a).
Lakhtakia, Akhlesh and Russell Messier, Selfsimilar sequences and chaos from Gauss sums, Computers & Graphics, Vol. 13, No. 1 (1989), pp. 5962 (Annotated scanned copy).


FORMULA

Completely multiplicative with a(2) = 3, a(p) = 0 for odd prime p.  Andrew Howroyd, Jul 27 2018


MATHEMATICA

a[n_] := With[{k = IntegerExponent[n, 2]}, If[n == 2^k, 3^k, 0]];
Array[a, 85] (* JeanFrançois Alcover, Aug 27 2019 *)


PROG

(PARI) a(n)={my(e=valuation(n, 2)); if(n == 2^e, 3^e, 0)} \\ Andrew Howroyd, Jul 27 2018


CROSSREFS

Sequence in context: A303633 A167004 A287632 * A239798 A019827 A329284
Adjacent sequences: A259343 A259344 A259345 * A259347 A259348 A259349


KEYWORD

nonn,easy,mult


AUTHOR

N. J. A. Sloane, Jun 27 2015


EXTENSIONS

More terms from Jon E. Schoenfield, Jun 28 2015


STATUS

approved



