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%I #20 Mar 19 2024 17:24:57
%S 11,13,13513,13577,135799,135791107,13579111307,1357911131503,
%T 13579111315171,135791113151719,1357911131517192157,
%U 13579111315171921231,135791113151719212325007,1357911131517192123252763,13579111315171921232527291,135791113151719212325272931
%N Smallest prime with concatenation of first n odd numbers as leading digits.
%C a(351) has 1002 digits. - _Michael S. Branicky_, Mar 19 2024
%H Michael S. Branicky, <a href="/A068837/b068837.txt">Table of n, a(n) for n = 1..350</a>
%o (Python)
%o from sympy import isprime
%o from itertools import count
%o def a(n):
%o prefix = int("".join(map(str, (2*i+1 for i in range(n)))))
%o if isprime(prefix): return prefix
%o for extra in count(1):
%o prefix *= 10
%o for i in range(10**extra):
%o t = prefix + i
%o if isprime(t): return t
%o print([a(n) for n in range(1, 17)]) # _Michael S. Branicky_, Mar 19 2024
%K nonn,base
%O 1,1
%A _Amarnath Murthy_, Mar 09 2002
%E More terms from _Benoit Cloitre_, Mar 10 2002
%E a(10) corrected by _Jayanta Basu_, Aug 08 2013
%E a(6)-a(8) and a(13) corrected and more terms from _Sean A. Irvine_, Mar 17 2024
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