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A164095
a(n) = 2*a(n-2) for n > 2; a(1) = 5, a(2) = 6.
7
5, 6, 10, 12, 20, 24, 40, 48, 80, 96, 160, 192, 320, 384, 640, 768, 1280, 1536, 2560, 3072, 5120, 6144, 10240, 12288, 20480, 24576, 40960, 49152, 81920, 98304, 163840, 196608, 327680, 393216, 655360, 786432, 1310720, 1572864, 2621440, 3145728
OFFSET
1,1
COMMENTS
Interleaving of A020714 and A007283 without initial term 3.
Partial sums are in A164096.
Binomial transform is A048655 without initial 1, second binomial transform is A161941 without initial 2, third binomial transform is A164037, fourth binomial transform is A161731 without initial 1, fifth binomial transform is A164038, sixth binomial transform is A164110.
FORMULA
a(n) = A070876(n)/3.
a(n) = (4-(-1)^n)*2^(1/4*(2*n-1+(-1)^n)).
G.f.: x*(5+6*x)/(1-2*x^2).
MATHEMATICA
LinearRecurrence[{0, 2}, {5, 6}, 50] (* or *) With[{nn=20}, Riffle[NestList[ 2#&, 5, nn], NestList[2#&, 6, nn]]] (* Harvey P. Dale, Aug 15 2020 *)
PROG
(Magma) [ n le 2 select n+4 else 2*Self(n-2): n in [1..40] ];
CROSSREFS
KEYWORD
nonn
AUTHOR
Klaus Brockhaus, Aug 10 2009
STATUS
approved