A164095 a(n) = 2*a(n-2) for n > 2; a(1) = 5, a(2) = 6.

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

Author

Klaus Brockhaus, Aug 10 2009

Keywords

• nonn

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.

Links

• Vincenzo Librandi, Table of n, a(n) for n = 1..1000
• Index entries for linear recurrences with constant coefficients, signature (0, 2).

Crossrefs

Cf. A020714 (5*2^n), A007283 (3*2^n), A164096, A048655, A161941, A164037, A161731, A164038, A164110, A070876.

Programs

Magma

[ n le 2 select n+4 else 2*Self(n-2): n in [1..40] ];

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 *)

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).