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Length of A185120(n): number of subsequent digits in the decimal expansion of e which form the next longer prime.
0

%I #10 Oct 01 2012 11:08:04

%S 1,2,25,90,456,608,1421,1469

%N Length of A185120(n): number of subsequent digits in the decimal expansion of e which form the next longer prime.

%C By definition, a strictly increasing sequence.

%C See A185120 for further comments and explanations.

%e The decimal expansion of e=exp(1)=2.718281828.... is split into

%e A185120(1) = 2 of length a(1)=1,

%e A185120(2) = 71 of length a(2)=2,

%e A185120(3) = 8281828459045235360287471 of length a(3)=25, etc.

%o (PARI) {default(realprecision,2000);e=exp(1)*.1; for( n=1,9e9, ispseudoprime(e\.1^n)|next; print1(n",");e=frac(e*10^n))}

%K nonn,base

%O 1,2

%A _M. F. Hasler_, Apr 01 2012