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A054258 Concatenation of n in base 2 up to base 10 and n in base 10 down to base 2 is prime, all numbers are interpreted as decimals. 2

%I

%S 2607,4007,4069,7597,12411,13583,23041,31113,32619,46187,48469,55777,

%T 61411,64387,71143,73837,84761,103559,123797,124043,126613,136509,

%U 142019,147449,183981,186889,200183,204219,214819,221101,224123,230977

%N Concatenation of n in base 2 up to base 10 and n in base 10 down to base 2 is prime, all numbers are interpreted as decimals.

%e a(1)=2607 prime onwards: 10100010111110120120220233404122002310413505735162607.

%e Case prime downwards is: 26073516505710413200234041222023310120120101000101111.

%Y Cf. A054256, A054257.

%K nonn,base

%O 0,1

%A _Patrick De Geest_, Feb 15 2000

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Last modified July 8 18:55 EDT 2020. Contains 335524 sequences. (Running on oeis4.)