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This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A371563 k=1..n times centrally deletable primes, or -1 if no such number exists.

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%I A371563 #29 Apr 20 2024 10:04:28
%S A371563 101,10009,1000151,100000609,10000003787,1000000210987,
%T A371563 100000003272019,10000000005012649,1000000000030109609,
%U A371563 100000000003242090733,10000000000090420109609,1000000000042957566399049,100000000000040357566399049,10000000000001990357566399049
%N A371563 k=1..n times centrally deletable primes, or -1 if no such number exists.
%C A371563 Smallest prime number that remains prime when removing k times (1 <= k <= n) the one or two central digits, depending on whether the prime number has an odd or even number of digits.
%H A371563 Jason Yuen, <a href="/A371563/b371563.txt">Table of n, a(n) for n = 1..89</a>
%H A371563 Jason Yuen, <a href="/A371563/a371563.py.txt">Python program</a>.
%e A371563 a(2) = 10009. This is because 10009, 1009, and 19 are all prime numbers, and there is no smaller prime number that satisfies this property.
%Y A371563 Cf. A225082.
%K A371563 nonn,base
%O A371563 1,1
%A A371563 _Jean-Marc Rebert_, Mar 27 2024
%E A371563 More terms from _Jason Yuen_, Apr 03 2024