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A164682
a(n) = 2*a(n-2) for n > 2; a(1) = 5, a(2) = 8.
4
5, 8, 10, 16, 20, 32, 40, 64, 80, 128, 160, 256, 320, 512, 640, 1024, 1280, 2048, 2560, 4096, 5120, 8192, 10240, 16384, 20480, 32768, 40960, 65536, 81920, 131072, 163840, 262144, 327680, 524288, 655360, 1048576, 1310720, 2097152, 2621440, 4194304
OFFSET
1,1
COMMENTS
Interleaving of A020714 and A000079 without initial terms 1, 2, 4.
First differences are in A162255.
Binomial transform is A135532 without initial terms -1, 3. Fourth binomial transform is A164537.
FORMULA
a(n) = (9-(-1)^n)*2^(1/4*(2*n-5+(-1)^n)).
G.f.: x*(5+8*x)/(1-2*x^2).
MATHEMATICA
LinearRecurrence[{0, 2}, {5, 8}, 60] (* Harvey P. Dale, Jul 20 2022 *)
PROG
(Magma) [ n le 2 select 2+3*n else 2*Self(n-2): n in [1..40] ];
CROSSREFS
Equals A094958 (numbers of the form 2^n or 5*2^n) without initial terms 1, 2, 4.
Cf. A020714 (5*2^n), A000079 (powers of 2), A162255, A135532, A164537.
Sequence in context: A314384 A196384 A325176 * A157482 A314385 A185001
KEYWORD
nonn,easy
AUTHOR
Klaus Brockhaus, Aug 21 2009
STATUS
approved