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A259091 Smallest k such that 2^k contains two adjacent copies of n in its decimal expansion. 6
53, 40, 43, 25, 18, 16, 46, 24, 19, 33, 378, 313, 170, 374, 361, 359, 64, 34, 507, 151, 348, 246, 314, 284, 349, 314, 261, 151, 385, 166, 156, 364, 65, 219, 371, 359, 503, 148, 155, 352, 349, 308, 247, 255, 192, 387, 165, 149, 171, 150, 210, 155, 209, 101, 505 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,1

COMMENTS

The multi-digit generalization of A171132. - R. J. Mathar, Jul 06 2015

LINKS

Chai Wah Wu, Table of n, a(n) for n = 0..1000

Popular Computing (Calabasas, CA), Two Tables, Vol. 1, (No. 9, Dec 1973), page PC9-16.

EXAMPLE

2^53 = 9007199254740992 contains two adjacent 0's.

PROG

(Python)

def A259091(n):

....s, k, k2 = str(n)*2, 0, 1

....while True:

........if s in str(k2):

............return k

........k += 1

........k2 *= 2 # Chai Wah Wu, Jun 18 2015

CROSSREFS

Cf. A006889, A131535, A131536, A259089, A063565, A259092.

Sequence in context: A033373 A289237 A171132 * A104936 A262908 A109648

Adjacent sequences:  A259088 A259089 A259090 * A259092 A259093 A259094

KEYWORD

nonn,base

AUTHOR

N. J. A. Sloane, Jun 18 2015

EXTENSIONS

More terms from Chai Wah Wu, Jun 18 2015

STATUS

approved

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Last modified July 25 10:40 EDT 2017. Contains 289792 sequences.