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a(1) = 2; thereafter a(n) = smallest number of copies of (the decimal expansion of) n that are needed to prefix A088061(n-1) with in order to get a prime (the prime being A088061(n)).
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%I #12 Oct 15 2017 21:58:28

%S 2,1,2,3,2,1,12,634,623

%N a(1) = 2; thereafter a(n) = smallest number of copies of (the decimal expansion of) n that are needed to prefix A088061(n-1) with in order to get a prime (the prime being A088061(n)).

%e a(4) = 3, A088061(3) = 33211 and A088061(4) = 44433211.

%o (PARI) x=0;n=-1;for(k=1,9,z=n;while(1,n++;x=x+k*10^n;if(ispseudoprime(x),print(z=n-z);break))) \\ _Dmitry Petukhov_, Oct 15 2017

%Y Cf. A088061.

%K base,more,nonn

%O 1,1

%A _Amarnath Murthy_, Sep 21 2003

%E a(8) from _David Wasserman_, Jul 01 2005

%E a(9) from _Dmitry Petukhov_, Oct 15 2017