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.
%I A238730 #10 Jun 09 2020 03:42:37 %S A238730 7,19,47,79,109,139,199,229,317,439,467,619,647,829,859,887,1039,1069, %T A238730 1097,1307,1429,1459,1489,1609,1669,1699,1789,1879,1999,2089,2389, %U A238730 2689,2719,3169,3259,3469,3677,3769,3919,4007,4099,4159,4219,4519,4729,4789,4937,5237,5419,5449,5479,5507,5659,5749,5869,6709,6829 %N A238730 The largest prime in each decade (10k,10k+10) containing at least three primes. %C A238730 The initial term 7 does not correspond to a "decadal prime triple" according to the strict definition of A008470. %H A238730 Robert Israel, <a href="/A238730/b238730.txt">Table of n, a(n) for n = 1..10000</a> %p A238730 f:= proc(k) local P; %p A238730 P:= select(isprime, [10*k+1,10*k+3,10*k+7,10*k+9]); %p A238730 if nops(P) >= 3 then max(P) fi %p A238730 end proc:f(0):= 7:map(f, [$0..1000]); # _Robert Israel_, Jun 08 2020 %o A238730 (PARI) p=0; for(d=1,999,2+p < (p=primepi(10*d)) && print1(precprime(d*10)",")) %Y A238730 Cf. A008470, A008471, A238713, A238715. %K A238730 nonn %O A238730 1,1 %A A238730 _M. F. Hasler_, Mar 03 2014