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A133337
a(3n) = 0, a(3n+1) = a(3n+2) = 5^n.
0
0, 1, 1, 0, 5, 5, 0, 25, 25, 0, 125, 125, 0, 625, 625, 0, 3125, 3125, 0, 15625, 15625, 0, 78125, 78125, 0, 390625, 390625, 0, 1953125, 1953125, 0, 9765625, 9765625, 0, 48828125, 48828125, 0, 244140625, 244140625, 0, 1220703125, 1220703125, 0
OFFSET
0,5
FORMULA
G.f.: -x*(1+x) / ( -1+5*x^3 ). - R. J. Mathar, Nov 07 2015
MATHEMATICA
LinearRecurrence[{0, 0, 5}, {0, 1, 1}, 50] (* Harvey P. Dale, Jun 24 2017 *)
PROG
(Magma) I:=[0, 1, 1]; [n le 3 select I[n] else 5*Self(n-3): n in [1..50]]; // Vincenzo Librandi, Sep 11 2015
CROSSREFS
Cf. A000351.
Sequence in context: A119380 A121212 A182787 * A279932 A022697 A286838
KEYWORD
nonn,easy
AUTHOR
Paul Curtz, Oct 19 2007
STATUS
approved