|
| |
| |
|
|
|
1, 4, 20, 104, 540, 2784, 14260, 72664, 368780, 1865744, 9416100, 47430024, 238548220, 1198333504, 6014037140, 30159664184, 151156234860, 757212830064, 3791790773380, 18981860359144, 95000927764700, 475371142699424, 2378321729000820, 11897472707018904
(list; graph; refs; listen; history; internal format)
|
|
|
|
OFFSET
| 0,2
|
|
|
LINKS
| Vincenzo Librandi, Table of n, a(n) for n = 0..1000
|
|
|
FORMULA
| a(n)= A000351(n)-A001045(2n).
a(n)=10a(n-1)-29a(n-2)+20a(n-3), as in A097165.
G.f.: (1-3x)^2/((1-x)(1-4x)(1-5x)). a(n)=A097165(n)-3*A097165(n-1). - R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Feb 27 2009
a(n)=(1/3)*(1+3*5^n-4^n), with n>=0 [From Paolo P. Lava (paoloplava(AT)gmail.com), Jan 26 2009]
|
|
|
PROG
| (MAGMA) [5^n+(1-4^n)/3: n in [0..30]]; // Vincenzo Librandi, Aug 07 2011
|
|
|
CROSSREFS
| Sequence in context: A186369 A093440 A168606 * A155181 A082761 A076035
Adjacent sequences: A155482 A155483 A155484 * A155486 A155487 A155488
|
|
|
KEYWORD
| nonn,easy
|
|
|
AUTHOR
| Paul Curtz (bpcrtz(AT)free.fr), Jan 23 2009
|
|
|
EXTENSIONS
| Edited, Lava definition adopted, and extended by R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Feb 27 2009
|
| |
|
|
