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A067469
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Numbers k such that 2 is the first digit of 2^k.
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8
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1, 8, 11, 18, 21, 28, 31, 38, 41, 48, 51, 58, 61, 68, 71, 81, 91, 101, 104, 111, 114, 121, 124, 131, 134, 141, 144, 151, 154, 161, 164, 171, 174, 184, 194, 197, 204, 207, 214, 217, 224, 227, 234, 237, 244, 247, 254, 257, 264, 267, 277, 287, 297, 300, 307, 310
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OFFSET
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1,2
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COMMENTS
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The asymptotic density of this sequence is log_10(3/2) = 0.176091... (A154580 - 1). - Amiram Eldar, Jan 27 2021
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LINKS
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MATHEMATICA
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Select[Range@ 310, First@ IntegerDigits[2^#] == 2 &] (* Michael De Vlieger, Oct 15 2018 *)
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PROG
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(GAP) Filtered([1..310], n->ListOfDigits(2^n)[1]=2); # Muniru A Asiru, Oct 14 2018
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CROSSREFS
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KEYWORD
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nonn,base
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AUTHOR
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STATUS
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approved
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