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Smallest prime ending in n, or 0 if no such prime exists.
2

%I #8 Feb 06 2019 17:18:40

%S 11,2,3,0,5,0,7,0,19,0,11,0,13,0,0,0,17,0,19,0,421,0,23,0,0,0,127,0,

%T 29,0,31,0,233,0,0,0,37,0,139,0,41,0,43,0,0,0,47,0,149,0,151,0,53,0,0,

%U 0,157,0,59,0,61,0,163,0,0,0,67,0,269,0,71,0,73,0,0,0,277,0,79,0,181,0

%N Smallest prime ending in n, or 0 if no such prime exists.

%H Antti Karttunen, <a href="/A070277/b070277.txt">Table of n, a(n) for n = 1..10000</a>

%o (PARI) A070277(n) = if(!(n%2) || !(n%5), isprime(n)*n, my(k=10^#digits(n)); forprime(p=n,oo,if(0==((p-n)%k), return(p)))); \\ _Antti Karttunen_, Feb 06 2019

%K base,nonn

%O 1,1

%A _Amarnath Murthy_, May 07 2002

%E More terms from Larry Reeves (larryr(AT)acm.org), Sep 26 2002