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%I A381511 #11 Mar 08 2025 17:31:54
%S A381511 139,3089,5749,20809,60539,110359,173359,618719,1294849,838249,
%T A381511 6877109,1895359,11188759,7621259,35560009,33803689,124956059,
%U A381511 92801029,142414669,378043979,229316459,390932389,1095750599,995151679,2174082649,2603726969,3402493709,1997191249
%N A381511 Smaller of two consecutive primes p and q, both ending with 9, such that q-p = 10n, or -1 if no such primes exist.
%e A381511 a(1) = 139, because 139 and 139 + 10 = 149 are two consecutive primes with the same last digit 9 and no smaller p has this property.
%o A381511 (PARI) a(n) = my(p=9); while (!isprime(p) || ((nextprime(p+1)-p) != 10*n), p+=10); p; \\ _Michel Marcus_, Feb 25 2025
%Y A381511 Cf. A101232, A140791, A380785, A381372. A381510.
%K A381511 nonn,base,new
%O A381511 1,1
%A A381511 _Jean-Marc Rebert_, Feb 25 2025

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