|
| |
|
|
A167747
|
|
a(n) = phi(6^n).
|
|
3
|
|
|
|
1, 2, 12, 72, 432, 2592, 15552, 93312, 559872, 3359232, 20155392, 120932352, 725594112, 4353564672, 26121388032, 156728328192, 940369969152, 5642219814912, 33853318889472, 203119913336832, 1218719480020992
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
|
OFFSET
|
0,2
|
|
|
LINKS
|
Vincenzo Librandi, Table of n, a(n) for n = 0..1000
D Bevan, D Levin, P Nugent, J Pantone, L Pudwell, Pattern avoidance in forests of binary shrubs, arXiv preprint arXiv:1510:08036, 2015
|
|
|
FORMULA
|
a(n+1) = 2*6^n. - Charles R Greathouse IV, Nov 12 2009
G.f.: (1-4x)/(1-6x). - Philippe Deléham, Oct 10 2011.
a(n) = ((8*n-4)*a(n-1)-12*(n-2)*a(n-2))/n, a(0)=1, a(1)=2. - Sergei N. Gladkovskii, Jul 19 2012
|
|
|
MATHEMATICA
|
Table[EulerPhi[6^n], {n, 0, 40}]
|
|
|
CROSSREFS
|
Sequence in context: A119921 A322276 A279154 * A018931 A062119 A181966
Adjacent sequences: A167744 A167745 A167746 * A167748 A167749 A167750
|
|
|
KEYWORD
|
nonn,easy
|
|
|
AUTHOR
|
Vladimir Joseph Stephan Orlovsky, Nov 10 2009
|
|
|
STATUS
|
approved
|
| |
|
|
