OFFSET
1,2
COMMENTS
3^(a(16)+1) contains exactly 16 consecutive 3's. - Bert Dobbelaere, Mar 20 2019
EXAMPLE
3^11 = 177147, which has two digits in a row.
MATHEMATICA
A215727[n_] := Module[{m = 0 , t}, t = Table[i, {i, 0, 9}, {n}];
While[True, If[ContainsAny[Subsequences[IntegerDigits[3^m], {n}], t], Return[m], m++]]; m]; Table[A215727[n], {n, 1, 14}] (* Robert Price, Oct 16 2018 *)
PROG
(Python)
def A215727(n):
l, x = [str(d)*n for d in range(10)], 1
for m in range(10**9):
s = str(x)
for k in l:
if k in s:
return m
x *= 3
return 'search limit reached'
# Chai Wah Wu, Dec 17 2014
CROSSREFS
KEYWORD
nonn,base,more
AUTHOR
V. Raman, Aug 22 2012
EXTENSIONS
a(12) from Chai Wah Wu, Dec 17 2014
a(13)-a(14) from Giovanni Resta, Apr 20 2016
a(15) from Bert Dobbelaere, Mar 04 2019
a(16)-a(17) from Bert Dobbelaere, Mar 20 2019
STATUS
approved