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A239747 Super-prime leaders: right-truncatable primes p with property that appending any single decimal digit to p does not produce a prime.

%I A239747 #21 Feb 16 2025 08:33:21
%S A239747 53,317,599,797,2393,3793,3797,7331,23333,23339,31193,31379,37397,
%T A239747 73331,373393,593993,719333,739397,739399,2399333,7393931,7393933,
%U A239747 23399339,29399999,37337999,59393339,73939133
%N A239747 Super-prime leaders: right-truncatable primes p with property that appending any single decimal digit to p does not produce a prime.
%C A239747 The name "super-prime leaders" is not due to the author.
%D A239747 Joe Roberts, Lure of the Integers, The Mathematical Association of America, 1992, p. 292.
%H A239747 Chris Caldwell, The Prime Glossary, <a href="https://t5k.org/glossary/xpage/RightTruncatablePrime.html">Right-truncatable prime</a>
%H A239747 G. L. Honaker, Jr. and Chris Caldwell, <a href="https://t5k.org/curios/cpage/10119.html">Prime Curios! 53</a>
%H A239747 Kvant magazine, <a href="http://kvant.mccme.ru/1970/11/naiprostejshie_prostye_chisla.htm">The simplest prime numbers</a>, (in Russian) No 11, 1979. (beware of typo)
%H A239747 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/TruncatablePrime.html">Truncatable Prime</a>
%H A239747 <a href="/index/Tri#tprime">Index entries for sequences related to truncatable primes</a>
%F A239747 A024770 INTERSECT A119289.
%e A239747 2393 belongs to this sequence because 2393, 239, 23 and 2 are all prime; 10*2393 + k, for k = 0 to 9, are all composite.
%o A239747 (PARI) f=1; for(n=2, 73939133, v=n; t=1; while(isprime(n), if(!Mod(f, n^2)==0, t=t*n); c=n; n=(c-lift(Mod(c, 10)))/10); if(n==0, f=f*t); n=v); s=Set(factor(f)[, 1]); for(k=1, #s, p=s[k]; if(!Mod(f, p^2)==0, print1(p, ", ")));
%Y A239747 Subsequence of A024770 and of A119289.
%K A239747 nonn,base,fini,full
%O A239747 1,1
%A A239747 _Arkadiusz Wesolowski_, Mar 26 2014