login
The OEIS is supported by the many generous donors to the OEIS Foundation.

 

Logo
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A244852 Least number k > 0 such that 3^k begins with exactly n consecutive increasing digits. 3
1, 17, 149, 146, 7997, 45419, 3972963, 27487124, 406680034 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,2
LINKS
EXAMPLE
3^17 = 129140163 begins with 2 consecutive increasing digits ('12'). Thus a(2) = 17.
PROG
(Python)
def a(n):
..for k in range(1, 10**5):
....st = str(3**k)
....count = 0
....if len(st) > n:
......for i in range(len(st)):
........if int(st[i]) == int(st[i+1])-1:
..........count += 1
........else:
..........break
......if count == n:
........return k
n = 0
while n < 10:
..print(a(n), end=', ')
..n += 1
CROSSREFS
Sequence in context: A196780 A208506 A299599 * A064102 A161497 A162328
KEYWORD
nonn,base,fini,full
AUTHOR
Derek Orr, Jul 07 2014
EXTENSIONS
a(7)-a(9) from Hiroaki Yamanouchi, Jul 10 2014
STATUS
approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified February 22 06:02 EST 2024. Contains 370240 sequences. (Running on oeis4.)