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%I #16 Apr 10 2017 23:42:39
%S 1,11,126,753,1923,32183,134708,1487139,23908603,215443469,106917811,
%T 15056809703,27354803113,681048619195,361160395301
%N a(n) = the first positive integer, not ending in zero, whose cube has a substring of exactly n identical digits.
%e a(3) = 126, as 126^3 = 2000376 contains a digit (0) repeated n (3) times.
%t a[n_] := Block[{k=1}, While[Mod[k, 10] == 0 || ! MemberQ[Length /@ Split[ IntegerDigits[ k^3]], n], k++]; k]; Array[a, 8] (* _Giovanni Resta_, Apr 10 2017 *)
%o (Python) import collections
%o import re
%o cur = 1
%o def repeat( num , reps ):
%o r = str(num)
%o n = 1
%o while n < reps:
%o r += str(num)
%o n += 1
%o return r;
%o while True:
%o k = 0
%o while k < 10:
%o rep = repeat(k,9)
%o while re.search(rep, str(cur**3)) != None:
%o if re.search(rep + str(k), str(cur**3)) == None:
%o print(str(cur) + ", " + str(cur**3))
%o rep += str(k)
%o else:
%o rep += str(k)
%o k += 1
%o cur += 1
%o if cur % 10 == 0:
%o cur += 1 #note: this will display all cubes with a substring of 9 repeated digits. To change this to n repeats, replace repeat(k,9) with repeat(k,n).
%Y Cf. A167712.
%K nonn,base,more
%O 1,2
%A _Jason Wang_, Apr 08 2017
%E a(10)-a(15) from _Giovanni Resta_, Apr 10 2017