A114743 a(1) =4, a(2) = 6, a(n+1) = least composite number of the form k*(a(n-1)) - a(n), not included earlier.

4, 6, 10, 8, 12, 20, 16, 24, 40, 32, 48, 80, 64, 96, 160, 128, 192, 320, 256, 384, 640, 512, 768, 1280, 1024, 1536, 2560, 2048, 3072, 5120, 4096, 6144, 10240, 8192, 12288, 20480, 16384, 24576, 40960, 32768, 49152, 81920, 65536, 98304, 163840, 131072

Offset

1,1

Comments

a(3n+1) = 2*a(3n-2)= 2^(n+2). a(3n+2) = 2*a(3n-1). = 3*2^(n+1). a(3n+3) = 2*a(3n). =5*2^(n).

Links

Table of n, a(n) for n=1..46.

Formula

a(n)=2*a(n-3). G.f.: -2*x*(2+3*x+5*x^2)/(-1+2*x^3). a(n)=2*A114744(n+1). [From R. J. Mathar, Jul 07 2009]

Crossrefs

Sequence in context: A363248 A084350 A028279 * A089546 A263483 A363700

Adjacent sequences: A114740 A114741 A114742 * A114744 A114745 A114746

Keyword

nonn

Author

Amarnath Murthy, Nov 15 2005

Extensions

More terms from R. J. Mathar, Jul 07 2009

Status

approved