|
|
A198852
|
|
a(n) = 4*8^n - 1.
|
|
2
|
|
|
3, 31, 255, 2047, 16383, 131071, 1048575, 8388607, 67108863, 536870911, 4294967295, 34359738367, 274877906943, 2199023255551, 17592186044415, 140737488355327, 1125899906842623, 9007199254740991, 72057594037927935
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
0,1
|
|
COMMENTS
|
In base 8, the numbers of this sequence are written 37, 377, 3777, 37777, ... and satisfy the A052148 condition. - Michel Marcus, Aug 23 2013
|
|
LINKS
|
|
|
FORMULA
|
a(n) = 8*a(n-1) + 7.
a(n) = 9*a(n-1) - 8*a(n-2) for n > 1.
G.f.: ( 3+4*x ) / ( (8*x-1)*(x-1) ). - R. J. Mathar, Oct 31 2011
|
|
PROG
|
(Magma) [4*8^n-1: n in [0..30]];
|
|
CROSSREFS
|
|
|
KEYWORD
|
nonn,easy
|
|
AUTHOR
|
|
|
STATUS
|
approved
|
|
|
|