OFFSET
1,2
COMMENTS
The first time "0" appears is in a(10). - Robert G. Wilson v, Feb 26 2013
REFERENCES
Julian Havil, Impossible?: Surprising Solutions to Counterintuitive Conundrums, Princeton University Press 2008
Ross Honsberger, Ingenuity in mathematics, Random House/Singer School Division 1970
EXAMPLE
n=1: 2^0 = 1
n=2: 2^7 = 128
n=3: 2^81 = 2417851639229258349412352
n=4: 2^283 has 86 decimals, "1234" appears on decimals 68 - 71:
2^283=
15541351137805832567355695254588151253139254712417116170014499277911234281641667985408
n=5: 2^684 has 206 decimals, "12345" appears on decimals 99 - 103.
MATHEMATICA
g[n_] := Block[{c = 0, k = 1}, While[k <= n, c = 10^Floor[1 + Log10[k]] c + k; k++]; c] (* from A007908 *); f[n_] := Block[{k = 0, s = ToString[g[n]]}, While[ StringPosition[ ToString[ 2^k], s] == {}, k++]; k]; Array[f, 10] (* Robert G. Wilson v, Feb 26 2013 *)
CROSSREFS
KEYWORD
nonn,base
AUTHOR
Eva-Maria Zschorn (e-m.zschorn(AT)zaschendorf.km3.de), Dec 18 2009
EXTENSIONS
a(6)-a(10) from Robert G. Wilson v, Feb 26 2013
a(11) from Giovanni Resta, Feb 26 2013
STATUS
approved