|
|
A156202
|
|
a(n) = 2*a(n-1)+3 for n > 1, a(1) = 10.
|
|
2
|
|
|
10, 23, 49, 101, 205, 413, 829, 1661, 3325, 6653, 13309, 26621, 53245, 106493, 212989, 425981, 851965, 1703933, 3407869, 6815741, 13631485, 27262973, 54525949, 109051901, 218103805, 436207613, 872415229, 1744830461, 3489660925, 6979321853, 13958643709
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
1,1
|
|
LINKS
|
|
|
FORMULA
|
a(n) = -3+13*2^(n-1).
|
|
MATHEMATICA
|
|
|
PROG
|
(Magma) I:=[10, 23]; [n le 2 select I[n] else 3*Self(n-1)-2*Self(n-2): n in [1..30]]; // Vincenzo Librandi, May 02 2012
(Python)
from itertools import accumulate
def f(an, _): return 2*an + 3
|
|
CROSSREFS
|
|
|
KEYWORD
|
nonn,easy
|
|
AUTHOR
|
|
|
EXTENSIONS
|
Definition and closed form corrected by Paolo P. Lava, Feb 13 2009
|
|
STATUS
|
approved
|
|
|
|