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

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A235869 Least number k such that 3^k begins with exactly n identical digits. 1
 1, 19, 33, 2061, 6563, 17853, 2319050, 2061700, 57587802, 2725111202, 6121395677, 79432391610, 5689239922828, 9667911135850, 253066675679888, 959406299366116, 2267148455007422, 182092146481798583, 1074950828335499452, 3586769629515088106, 72389675081649855753 (list; graph; refs; listen; history; text; internal format)
 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 Sequence in context: A223608 A146438 A146571 * A140601 A031206 A214231 Adjacent sequences:  A235866 A235867 A235868 * A235870 A235871 A235872 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

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.

Last modified June 25 22:13 EDT 2022. Contains 354868 sequences. (Running on oeis4.)