

A165192


a(0) = 1, a(1) = 2, a(3) = 3, a(n) = a(n1)  a(n3).


0



1, 2, 3, 2, 0, 3, 5, 5, 2, 3, 8, 10, 7, 1, 11, 18, 17, 6, 12, 29, 35, 23, 6, 41, 64, 58, 17, 47, 105, 122, 75, 30, 152, 227, 197, 45, 182, 379, 424, 242, 137, 561, 803, 666, 105, 698, 1364, 1469, 771, 593, 2062, 2833, 2240, 178
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OFFSET

0,2


LINKS

Table of n, a(n) for n=0..53.
Index entries for linear recurrences with constant coefficients, signature (1, 0, 1).


FORMULA

a(n) = (1)^n*A104771(n). G.f.: (1+x+x^2)/(1x+x^3).


EXAMPLE

a(3) = 2 because 2 = 3  1 where the 1, 3 on the right of the equals sign are the first and third terms of the series.


MATHEMATICA

LinearRecurrence[{1, 0, 1}, {1, 2, 3}, 80] (* Harvey P. Dale, Apr 13 2012 *)


PROG

(Python) series = [1, 2, 3] for i in range(2, 30): .series.append((series[i]  series[i1])+(series[i1]series[i2])) print series


CROSSREFS

Cf. A104771
Sequence in context: A303121 A332921 A239579 * A104771 A307688 A056888
Adjacent sequences: A165189 A165190 A165191 * A165193 A165194 A165195


KEYWORD

easy,sign


AUTHOR

Ben Paul Thurston, Sep 06 2009


EXTENSIONS

Offset corrected and recurrence simplified by R. J. Mathar, Sep 08 2009
More terms from Harvey P. Dale, Apr 13 2012


STATUS

approved



