OFFSET
1,2
COMMENTS
a(7) > 200000.
The repeating digits that correspond to these data values are {3, 1, 5, 2, 2, 1, 1, 7, 2, 8, 1} respectively.
a(12) > 2 * 10^10 - Hiroaki Yamanouchi, Jul 13 2014
LINKS
Hiroaki Yamanouchi, Table of n, a(n) for n = 1..100
EXAMPLE
3^19 = 1162261467 begins with two identical digits ('11'). Thus a(2) = 19.
PROG
(Python)
def b(n):
for k in range(1, 2*10**5):
st = str(3**k)
count = 0
if len(st) >= n:
for i in range(len(st)):
if st[i] == st[0]:
count += 1
else:
break
if count == n:
return k
n = 1
while n < 10:
print(b(n), end=', ')
n += 1
CROSSREFS
KEYWORD
nonn,base
AUTHOR
Derek Orr, Jun 13 2014
EXTENSIONS
a(7)-a(11) from Hiroaki Yamanouchi, Jul 13 2014
a(12)-a(21) from Hiroaki Yamanouchi, May 31 2015
STATUS
approved
