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%I #21 May 17 2019 14:43:55
%S 242,42,43,83,44,41,157,24,39,50,949,1841,3661,1798,1701,1161,1806,
%T 391,1890,2053,950,1164,2354,1807,3816,1800,1799,818,1702,2115,904,
%U 1798,1807,2270,392,1699,3022,394,2054,1758,1804,2300,2720,2403,3396,1133,1808,3820
%N Smallest k such that 2^k contains three adjacent copies of n in its decimal expansion.
%C The multi-digit generalization of A171242. - _R. J. Mathar_, Jul 06 2015
%H Chai Wah Wu, <a href="/A259092/b259092.txt">Table of n, a(n) for n = 0..1000</a>
%H Popular Computing (Calabasas, CA), <a href="/A094776/a094776.jpg">Two Tables</a>, Vol. 1, (No. 9, Dec 1973), page PC9-16.
%e 2^242 = 7067388259113537318333190002971674063309935587502475832486424805170479104 contains three adjacent 0's.
%t Table[k = 0; While[! SequenceCount[IntegerDigits[2^k], Flatten[ConstantArray[IntegerDigits[n], 3]]] > 0, k++]; k, {n, 0, 50}] (* _Robert Price_, May 17 2019 *)
%o (Python)
%o def A259092(n):
%o ....s, k, k2 = str(n)*3, 0, 1
%o ....while True:
%o ........if s in str(k2):
%o ............return k
%o ........k += 1
%o ........k2 *= 2 # _Chai Wah Wu_, Jun 18 2015
%Y Cf. A006889, A131535, A131536, A259089, A063565, A259091.
%K nonn,base
%O 0,1
%A _N. J. A. Sloane_, Jun 18 2015
%E More terms from _Chai Wah Wu_, Jun 18 2015
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