A147535 a(n) = 2*4^n+4*3^n-2^n.

5, 18, 64, 228, 820, 2988, 11044, 41388, 157060, 602508, 2332324, 9095148, 35676100, 140586828, 555986404, 2204846508, 8762055940, 34876167948, 138988373284, 554404335468, 2212969344580

Offset

0,1

Links

Table of n, a(n) for n=0..20.

Formula

a(n) = 9*a(n-1)-26*a(n-2)+24*a(n-3) = 2*4^n+4*3^n-2^n. G.f.: (5-27x+32x^2)/((1-2x)(1-3x)(1-4x)). [R. J. Mathar, Nov 09 2008]

Crossrefs

Sequence in context: A284840 A301749 A222373 * A184309 A051944 A153373

Adjacent sequences: A147532 A147533 A147534 * A147536 A147537 A147538

Keyword

nonn,easy,less

Author

Roger L. Bagula, Nov 06 2008

Extensions

Meaningful name from Joerg Arndt, Dec 26 2022

Status

approved